Prepare release v1.55.1

[sfc-gh-mayliu]

Automated release cut by /release-python. Target version: v1.55.1.

Review checklist (cut sanity + release-notes approval):

• Release notes / Changelog Update Approval from Product Manager (Qinyi Ding)
• Version bump correct (for a hotfix, curate the CHANGELOG entries under the new header)
• Dependency alignment setup.py <-> recipe/meta.yaml (verify manually)
• AST goldens: only client_version bumped; regenerate with the monorepo Unparser only if AST-generation logic changed (out of scope here)

[snowflake-security-bot]

Snowflake Security Review

Security grade: A — Passed ✅

This PR was classified as LOW risk by the automated pre-screen.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 94.19%. Comparing base (b1173b1) to head (29df4bc).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4408      +/-   ##
==========================================
- Coverage   95.47%   94.19%   -1.28%     
==========================================
  Files         176      176              
  Lines       45271    45271              
  Branches     7759     7759              
==========================================
- Hits        43222    42644     -578     
- Misses       1269     1832     +563     
- Partials      780      795      +15     

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[snowflake-security-bot]

Snowflake Security Review

Security grade: A — Passed ✅

This PR was classified as LOW risk by the automated pre-screen.

[snowflake-security-bot]

Snowflake Security Review

Security grade: A — Passed ✅

This PR was classified as LOW risk by the automated pre-screen.