ci: add labels after resetting existing semantic version

[zimeg]

Changelog

Oncemore nothing but fixes for build processes...

Summary

This PR follows #557 to use the latest flags of the gh CLI in resetting labels.

Preview

unknown flag: --label

🔗 https://github.com/slackapi/slack-cli/actions/runs/26258890693/job/77287734796#step:7:38

Notes

Let's hope this is correct for #553.

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.

[zimeg]

🚢 Let's now merge this because #557 was not enough.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 71.68%. Comparing base (d7863af) to head (1c3a685).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@ Coverage Diff @@## main #558 +/- ##
==========================================
- Coverage 71.69% 71.68% -0.02% 
==========================================
Files 226 226 Lines 19115 19115 ==========================================
- Hits 13705 13703 -2 - Misses 4207 4208 +1 - Partials 1203 1204 +1 

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