Fix macro rules in accordance with edition 2024

[matheus-consoli]

this crate does not compile under edition 2024 because of one rule inside a macro

error: patterns are not allowed to reset the default binding mode in Edition 2024
   --> src/future/join/tuple.rs:249:21
    |
249 |                 let ($(ref mut $F,)+) = this.outputs;
    |                     -^^^^^^^^^^^^^^^^
    |                     |
    |                     help: desugar the match ergonomics: `&mut`

places to fix:

• futures-concurrency/src/future/join/tuple.rs

  Line 249 in abc7a90

  let ($(ref mut $F,)+) = this.outputs;

• futures-concurrency/src/future/try_join/tuple.rs

  Line 283 in abc7a90

  let ($(ref mut $F,)+) = this.outputs;

• maybe a couple of others?

[reneleonhardt]

@matheus-consoli If you want you can try my PR.

I had to revert most changes cargo fix --edition made, but at least your findings were spot-on 😅
And I had to downgrade a transitive dependency to make all checks happy.