Update MSRV to 1.51, enable cargo resolver = "2"

[notmandatory]

Description

This is required to keep using dependencies that have switched to MSRV 1.51 which requires the resolver version 2: tiny-bip39, ahash, and object.

Notes to the reviewers

Current Debian stable (bullseye) includes Rust 1.48.0, and testing (bookworm) includes Rust 1.50.0. If this is a concern I'm open to other suggestions on how to avoid running into the resolver errors we've been getting hit with lately.

Prior to merging this PR our branch checks will need to be updated to require the 1.51.0 tests instead of the ones for 1.48.0.

Checklists

All Submissions:

• I've signed all my commits
• I followed the contribution guidelines
• I ran cargo fmt and cargo clippy before committing

New Features:

• I've updated CHANGELOG.md

Bugfixes:

• This pull request breaks the existing API, Requires update to Rust 1.51+
• I've added tests to reproduce the issue which are now passing
• I'm linking the issue being fixed by this PR

[rajarshimaitra]

tACK.

To me it seems MSRV to 1.51 is the right way to go.

Although interested to know if there's any hidden catch.

[afilini]

Concept ACK on bumping the MSRV, but I would discuss about this in the call to see if we can get away with a lower version. The two errors I had to fix for #454 for instance were not related to the resolver, so maybe we can find a compromise to keep using a version that is more widely available without having too many issues.

[notmandatory]

Rebased on master following #454

[notmandatory]

I have a proposal for an updated MSRV policy in #331 and based on decision there will update this PR.

[notmandatory]

Closing since #454 and #462 fixes our immediate issues. Will continue discussion on #331.