The 1.55.0 pre-release is ready for testing. The release is scheduled for this Thursday, September 9th. Release notes can be found here.
You can try it out locally by running:
RUSTUP_DIST_SERVER=https://dev-static.rust-lang.org rustup update stable
The index is https://dev-static.rust-lang.org/dist/2021-09-06/index.html. You can leave feedback on the internals thread.