feat(iroh-net)!: upgrade to Quinn 0.11 and Rustls 0.23 (#2595)

## Description

Upgrades the Quinn and Rustls dependencies. This touches a lot of
dependencies and affects a lot of the internal API due to the changes in
Quinn.

## Breaking Changes

- `iroh::net::endpoint::Endpoint::accept` now returns `Incoming` instead
of `Connecting`. This allows rejecting incoming connections earlier,
notify the initiating side to retry later and more. To get back
`Connecting`, simply use `Incoming::accept()`. If all you did with
`Connecting` before was to `.await` it, you can do the same with
`Incoming`, too, and get back a `Connection`.
- Removed `iroh::net::endpoint::Builder::concurrent_connections`. The
amount of concurrent connections is now controlled by either calling
`Incoming::accept` or `Incoming::refuse` after `Endpoint::accept`.

## Notes & open questions

See #2273 for the tracking issue coordinating all this work. This is the
last piece of the puzzle.

## Change checklist

- [x] Self-review.
- [x] Documentation updates following the [style
guide](https://rust-lang.github.io/rfcs/1574-more-api-documentation-conventions.html#appendix-a-full-conventions-text),
if relevant.
- [x] Tests if relevant.
- [x] All breaking changes documented.

---------

Co-authored-by: dignifiedquire <[email protected]>
Co-authored-by: Philipp Krüger <[email protected]>

.github/workflows/tests.yaml

@@ -98,6 +98,7 @@ jobs:
           else
             targets="--lib --bins"
           fi
+          echo cargo check -p $i $FEATURES $targets
           cargo check -p $i $FEATURES $targets
         done
       env: