[chore] Update release doc to remove step 1 of releasing contrib

[jade-guiton-dd]

Description

Once contrib#38534 is merged, the manual changes that were necessary in step 1 of releasing contrib should now be included in step 2 (the Prepare Release CI workflow). This PR updates the release doc to remove step 1.

Link to tracking issue

Updates #12294

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 92.00%. Comparing base (27ff489) to head (7716a9d).
Report is 10 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main   #12632   +/-   ##
=======================================
  Coverage   92.00%   92.00%           
=======================================
  Files         477      477           
  Lines       26156    26162    +6     
=======================================
+ Hits        24064    24070    +6     
  Misses       1669     1669           
  Partials      423      423           

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[mx-psi]

cc @evan-bradley for visibility: this is a small change on the release for Monday

[jade-guiton-dd]

I would be cautious and say "hopefully small"