Enable Swift 6.2 jobs in CI

[rnro]

Motivation:

Swift 6.2 has been released, we should add it to our CI coverage.

Modifications:

Add additional Swift 6.2 jobs where appropriate in main.yml, pull_request.yml

Result:

Improved test coverage.

[guoye-zhang]

We need to delete this line to fix 6.2 builds:

extension LockStorage: @unchecked Sendable {}