chore: update rust toolchain, migrate to 2024 edition

[tediou5]

let_chains is already stable.
duration_constructors_lite was forked from duration_constructors and contains only the non-controversial parts(rust-lang/rust#120301).

Most of the changes are simply moves triggered by the updated fmt rules.

The only difference comes from the updated lifetime-capture rules in RPIT(https://doc.rust-lang.org/edition-guide/rust-2024/rpit-lifetime-capture.html):

1. subspace/crates/subspace-farmer/src/farm/plotted_pieces.rs

   Line 64 in c65631e

   ) -> Option<impl Future<Output = Option<Piece>> + use<FarmIndex>> {

2. https://github.com/tediou5/subspace/blob/c65631e55bd8076f0b75ad790f657ab79dff8a89/crates/subspace-farmer/src/single_disk_farm/farming.rs#L131-L143

Code contributor checklist:

• I have read, understood and followed contributing guide

[vedhavyas]

Would be ideal if you could derive the edition from the workspace Cargo.toml.

Rest looks good

[vedhavyas]

more on the use bound: https://blog.rust-lang.org/2024/09/05/impl-trait-capture-rules/

[teor2345]

Thanks for this PR!

1. Please run clippy before pushing changes.

2. This PR is one big commit, which makes it harder to review.

To split it into different commits, you could do something like:

• one commit which inherits the 2021 edition manually (or mostly automatically using search and replace)
• another commit which switches to the 2024 edition automatically, with the exact command used to do that copied into the commit message
• a commit for cargo clippy fix --all
• a commit for any manual clippy fixes that are needed
• any other required manual changes, in separate commits for each type of change
• a commit for rustfmt (with the command in the commit message)

Having separate commits is not a blocker for me, but I might not have time to review all the commits in detail. Putting the commands in each commit makes review easier, because I can run the command and make sure it produces the same output.

Would be ideal if you could derive the edition from the workspace Cargo.toml.

3. Here's how editions can be inherited:
   https://doc.rust-lang.org/cargo/reference/workspaces.html#the-package-table

4. There's also an unnecessary (but technically correct) use<> I'd like to fix up.

[teor2345]

As far as I can see, the use<FarmIndex> is only required for debugging, so it can be removed by doing:

let farm_index = usize::from(piece_details.farm_index);

near the start of the function.

This change doesn't need to be in this PR.

[teor2345]

It seems like rustfmt changes the type/function ordering in use between editions. I wonder if this would be better done in a separate PR?

reorder_imports = false might keep things the way they are in this PR.
https://github.com/rust-lang/rustfmt/blob/master/Configurations.md#reorder_imports

This is not a blocker for me.

[tediou5]

I see this as part of the version migration, so I’ve moved it into a separate commit. I hope that makes it easier for you to review.

[tediou5]

Following the review suggestions, I’ve split it into different commits.

[tediou5]

Just rebased main

[vedhavyas]

@tediou5 can you resolve conflicts please ?

[tediou5]

@tediou5 can you resolve conflicts please ?

Sure, I'll resolve it later.