Prepare 1.2.2 release

[mpol1t]

Summary

• bump package version to 1.2.2
• add changelog entry for the ws_opts websocket upgrade bugfix now on main

Validation

• I ran the relevant local checks
• I updated documentation if needed

Notes

• Verified with mix test in a clean worktree for the release branch contents.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 92.97%. Comparing base (00d5c41) to head (9a6bc01).
⚠️ Report is 29 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #122      +/-   ##
==========================================
+ Coverage   92.93%   92.97%   +0.03%     
==========================================
  Files           6        6              
  Lines         184      185       +1     
==========================================
+ Hits          171      172       +1     
  Misses         13       13              

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