ci: create cyborg for all heavy GitHub integrated actions

[tisonkun]

I hereby agree to the terms of the GreptimeDB CLA.

Refer to a related PR or issue link (optional)

What's changed and what's your intention?

Generally replace some bot-like automation in cyborg. This has the following advantages:

1. Less external dependencies.
2. Full featured actions/toolkit support, better integration with the GHA API.

This patch replace the unassign action with TS-written cyborg. Later I will replace doc-issue.yml, doc-label.yml and pr-title-checker.yml.

Checklist

• I have written the necessary rustdoc comments.
• I have added the necessary unit tests and integration tests.
• This PR does not require documentation updates.

[tisonkun]

Here is a successful run: https://github.com/GreptimeTeam/greptimedb/actions/runs/8917184960/job/24489836650

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 85.63%. Comparing base (65d47ba) to head (7a7dabc).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3852      +/-   ##
==========================================
+ Coverage   85.60%   85.63%   +0.02%     
==========================================
  Files         955      955              
  Lines      163262   163262              
==========================================
+ Hits       139758   139804      +46     
+ Misses      23504    23458      -46     

[evenyag]

CI Master👍

[waynexia]

🚀