Remove test-cross CI job definition

One or both of these matrix jobs, or related ones, be brought back
some day, probably to run only specific tests that have failed in
the past and started passing.

The files for local testing with `cross` (and associated `justfile`
recipes) are kept.

Author: EliahKagan

.github/workflows/ci.yml

@@ -327,42 +327,6 @@ jobs:
       - name: Test (nextest)
         run: cargo nextest run --target $env:TARGET --workspace --no-fail-fast size
 
-  # FIXME: *If* this is kept, then remove `fail-fast: false`, run only a subset of the tests unless
-  #        building and running the whole test suite is fast, and add a `Swatinem/rust-cache` step.
-  test-cross:
-    runs-on: ubuntu-latest
-
-    strategy:
-      matrix:
-        nickname: [ android, s390x ]
-        include:
-          - nickname: android
-            target: armv7-linux-androideabi
-          - nickname: s390x
-            target: s390x-unknown-linux-gnu
-      fail-fast: false
-
-    steps:
-      - uses: actions/checkout@v4
-      - name: Install Rust
-        uses: dtolnay/rust-toolchain@master
-        with:
-          toolchain: stable
-          targets: ${{ matrix.target }}
-      - uses: extractions/setup-just@v3
-      - name: Install cross
-        uses: taiki-e/install-action@v2
-        with:
-          tool: cross
-      - name: Configure binfmt_misc for QEMU
-        run: docker run --rm --privileged multiarch/qemu-user-static --reset -p yes
-      - name: Build cross image
-        run: just cross-image ${{ matrix.target }}
-      - name: Test (unit)
-        env:
-          RUST_BACKTRACE: '1'
-        run: just cross-test-${{ matrix.nickname }}
-
   lint:
     runs-on: ubuntu-latest
 
@@ -520,7 +484,6 @@ jobs:
     env:
       # List all jobs that are intended NOT to block PR auto-merge here.
       EXPECTED_NONBLOCKING_JOBS: |-
-        test-cross
         cargo-deny-advisories
         wasm
         tests-pass