chore(release): version 3.42.0

[zimeg]

Summary

This PR tags the changes of main as latest version 3.42.0: https://github.com/slackapi/python-slack-sdk/milestone/118?closed=1

Category

• slack_sdk.web.WebClient (sync/async) (Web API client)
• slack_sdk.signature (Request Signature Verifier)
• slack_sdk.oauth (OAuth Flow Utilities)
• slack_sdk.models (UI component builders)
• /docs (Documents)
• tests/integration_tests (Automated tests for this library)

Requirements

• I've read and understood the Contributing Guidelines and have done my best effort to follow them.
• I've read and agree to the Code of Conduct.
• I've run python3 -m venv .venv && source .venv/bin/activate && ./scripts/run_validation.sh after making the changes.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 84.13%. Comparing base (e69ba32) to head (da22bdc).
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@ Coverage Diff @@## main #1876 +/- ##
==========================================
+ Coverage 84.10% 84.13% +0.02% 
==========================================
Files 117 117 Lines 13337 13337 ==========================================
+ Hits 11217 11221 +4 + Misses 2120 2116 -4 

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[zimeg]

🚀 Onward to publish!