Mutex should be ~Copyable

[swhitty]

Updates Mutex to support non copyable's aligning with the Swift 6 API.

struct Mutex<Value: ~Copyable>: ~Copyable

Deprecates AllocatedLock as it is now longer used, instead a single class is used for the storage of both he value and lock.

Note: The windows version does not yet support these ~Copyable annotations.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 100.00%. Comparing base (c7c4773) to head (da6e0f3).

Additional details and impacted files

@@             Coverage Diff             @@
##             main        #5      +/-   ##
===========================================
+ Coverage   97.75%   100.00%   +2.24%     
===========================================
  Files           5         5              
  Lines         267       268       +1     
===========================================
+ Hits          261       268       +7     
+ Misses          6         0       -6     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.