Move release script to GitHub Action

[lucacome]

Proposed changes

Moves the release script to GitHub Actions as a first step to fully automate the release process.
Removes the step that keeps in sync the helm chart docs, since it's not pure markdown anymore.

[codecov]

Codecov Report

Merging #4592 (ea4c0b5) into main (c76d2ac) will increase coverage by 0.03%.
Report is 1 commits behind head on main.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main    #4592      +/-   ##
==========================================
+ Coverage   51.95%   51.99%   +0.03%     
==========================================
  Files          59       59              
  Lines       16967    16967              
==========================================
+ Hits         8816     8822       +6     
+ Misses       7854     7850       -4     
+ Partials      297      295       -2     

see 2 files with indirect coverage changes

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[shaun-nx]

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