perf: desugar remaining #[async_trait] stubs capturing Expr/LogicalPlan

[alamb]

Which issue does this PR close?

• Addresses Building project takes a *long* time (esp compilation time for datafusion core crate) #13814
• Follow on to perf(catalog): cut datafusion-catalog compile time ~6x #24325, perf(session): cut datafusion-session compile time ~1.7x #24326, perf(core): cut datafusion core compile time ~10x #24329 and perf(catalog-listing): cut datafusion-catalog-listing compile time ~4.4x #24330

Rationale for this change

Applies the same rewrite as the four PRs above to the remaining #[async_trait] methods on the serial build path whose futures capture Expr/LogicalPlan-reaching types (so their Send/Sync proofs are re-proved per method in a non-empty ParamEnv):

• UnsupportedQueryPlanner::create_physical_plan (datafusion-session) — captures &LogicalPlan
• ExtensionPlanner::plan_table_scan default body (datafusion-session) — captures &TableScan, which holds Vec<Expr>
• EmptyTable::scan (datafusion-catalog) — captures &[Expr]
• TestTableProvider::scan (datafusion core; test_util compiles into the lib unconditionally) — captures &[Expr]

What changes are included in this PR?

Each method becomes the hand-written desugaring of what #[async_trait] generates (verified against -Zunpretty=expanded output), with no coroutine capturing the arguments:

• The stubs (create_physical_plan, plan_table_scan, TestTableProvider::scan) return ready(..) or a captureless async block directly.
• EmptyTable::scan has no .await, so its body moves verbatim to a plain inherent fn wrapped in ready(..) (same as TestTableFactory::create_inner in perf(core): cut datafusion core compile time ~10x #24329).
• plan_table_scan keeps its Self: Sync + 'async_trait bound so the public trait signature is unchanged.

Each converted method carries the explanatory comment from #24362.

Are these changes tested?

Functionally: cargo fmt --check, cargo clippy -p datafusion-catalog -p datafusion-session --all-targets, cargo clippy -p datafusion --lib, cargo test -p datafusion-catalog -p datafusion-session, and cargo test -p datafusion --lib all pass. The compiler checks each rewritten signature against its trait declaration.

Compile-time impact is not yet measured (my machine is too noisy); this PR is a draft until the numbers below are collected.

Compile-time measurements to run (on a quiet machine)

Interleaved A/B of each affected crate's unit, alternating main and this branch at least 3 times each so machine drift cancels out (the methodology from #24325–#24330):

# once per checkout: warm the dependency graph
cargo build -p datafusion

# one round (repeat >=3x, alternating branches):
cargo clean -p datafusion-session -p datafusion-catalog -p datafusion
time cargo rustc -p datafusion-session --lib
time cargo rustc -p datafusion-catalog --lib
time cargo rustc -p datafusion --lib

Expected: a drop in datafusion-session (which had ~0.65s of evaluate_obligation remaining after #24326 in the standalone build, several times more in the feature-unified build) and a smaller drop in datafusion-catalog and core. EmptyTable/TestTableProvider are unproven — they did not appear in the per-impl profiles of #24325/#24329 — so it is worth confirming their marginal contribution before merging, e.g. by reverting one file at a time.

To attribute the change to the trait solver rather than noise:

# cargo install --git https://github.com/rust-lang/measureme summarize
RUSTFLAGS="-Zself-profile=/tmp/self-profile" cargo +nightly rustc -p datafusion-session --lib
summarize summarize $(ls -t /tmp/self-profile/*.mm_profdata | head -1) | grep -E "evaluate_obligation|Total"

Are there any user-facing changes?

No. After macro expansion the method signatures are identical to before, including plan_table_scan's Self: Sync bound.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 28.07018% with 41 lines in your changes missing coverage. Please review.
✅ Project coverage is 81.18%. Comparing base (571477c) to head (d868efb).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
datafusion/session/src/planner.rs	0.00%	28 Missing ⚠️
datafusion/core/src/test_util/mod.rs	0.00%	13 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #24370      +/-   ##
==========================================
- Coverage   81.19%   81.18%   -0.02%     
==========================================
  Files        1110     1110              
  Lines      388616   388677      +61     
  Branches   388616   388677      +61     
==========================================
  Hits       315534   315534              
- Misses      54500    54555      +55     
- Partials    18582    18588       +6     

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[alamb]

I had codex run some tests on a gcp machine and this PR doesn't improve compialtion speed

Details below:

Compared PR head d868efb against its base 571477c, using 5 interleaved rounds. A full cargo clean and warm build were performed for each checkout; affected package artifacts were cleaned before each timed round.

Crate	Main times (s)	PR times (s)	Main mean (s)	PR mean (s)
datafusion-session	36.56, 1.44, 1.44, 1.43, 1.46	36.35, 1.46, 1.46, 1.46, 1.46	8.466	8.438
datafusion-catalog	36.49, 3.47, 3.48, 3.58, 3.47	36.53, 3.50, 3.51, 3.59, 3.52	10.098	10.130
datafusion	14.51, 14.43, 14.46, 14.41, 14.45	14.56, 14.50, 14.44, 14.44, 14.49	14.452	14.486

The first session/catalog measurements are cold-build outliers. Excluding round 1, the PR was approximately 1.2% slower for session, 0.9% slower for catalog, and 0.2% slower for core—within normal timing noise on this machine.

Exact benchmark commands

# once per checkout
cargo clean
cargo build -p datafusion --quiet

# each round, before the timed commands
cargo clean -p datafusion-session -p datafusion-catalog -p datafusion --quiet

# timed commands
/usr/bin/time -f "RESULT package=datafusion-session seconds=%e" cargo rustc -p datafusion-session --lib --quiet
/usr/bin/time -f "RESULT package=datafusion-catalog seconds=%e" cargo rustc -p datafusion-catalog --lib --quiet
/usr/bin/time -f "RESULT package=datafusion seconds=%e" cargo rustc -p datafusion --lib --quiet