Describe the bug
The recently released version 0.23.18 bumped the MSRV from 1.63 to 1.71 in a patch release. This was done in #2220 with seemingly no strong necessity, IIUC mostly to adopt the let ... else syntax?

We are downstream users of rustls through a variety of intermediate dependencies and do rely on MSRV 1.63 (building on Debian stable). Shipping this MSRV bump hence breaks our builds. While this is a common issue, we're usually 'okay' with doing some pinning to ensure we can maintain the 1.63 MSRV.

However, in this case we really, really don't want to pin rustls back due to security considerations. Given that the bump happened casually on a patch release means that we have no 'stable' channel that we can keep using (i.e., for which security updates would be provided).

As this doesn't only concern one crate/project, but quite a few projects that depend on or try to maintain an MSRV of 1.63, I'd like to ask you to reconsider the MSRV bump, i.e, the changes in #2220.

As we see it, possible solutions could be, for example:

• Revert Move MSRV to 1.71 #2220, simply stay on MSRV 1.63, at least until the next Debian stable release ships, or
• Intermittently revert Move MSRV to 1.71 #2220, possibly ship it as part of a minor release, and committing to providing backports of security fixes to the 0.23 branch.