Remove Go module grouping in renovate

[sjberman]

The grouping of Go modules is causing some issues, mainly when Gateway API dependencies are included. Since we have to update these manually, it blocks other dependencies from being merged.

It's also good to update Go modules individually in the case of a breakage, it's easier to find and roll back the dependency that broke.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 86.09%. Comparing base (eb04371) to head (9b51a88).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4398      +/-   ##
==========================================
- Coverage   86.14%   86.09%   -0.05%     
==========================================
  Files         132      132              
  Lines       14359    14359              
  Branches       35       35              
==========================================
- Hits        12369    12363       -6     
- Misses       1786     1790       +4     
- Partials      204      206       +2     

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