chore: use common PAT instead of rudder-server-bot

[lvrach]

Description

secrets.GH_PAT is using rudder-server-bot Personal Access Token. We want to remove the rudder-server-bot account and instead use secrets.PAT, already used in other Github actions

Linear Ticket

https://linear.app/rudderstack/issue/PIPE-388/remove-rudder-server-bot-account-from-github

Security

• The code changed/added as part of this pull request won't create any security issues with how the software is being used.

[codecov]

Codecov Report

All modified lines are covered by tests ✅

Comparison is base (5f3820f) 70.38% compared to head (eb59771) 70.48%.
Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3952      +/-   ##
==========================================
+ Coverage   70.38%   70.48%   +0.09%     
==========================================
  Files         357      357              
  Lines       53646    53646              
==========================================
+ Hits        37758    37810      +52     
+ Misses      13620    13571      -49     
+ Partials     2268     2265       -3     

see 9 files with indirect coverage changes

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