Update tests instructions for common troubleshooting

[salonichf5]

Proposed changes

Adds new make instruction to update firewall IP rule when running into VM connectivity issues with GCP.

Testing: Ran it manually and could access VM even after IP changes. make add-local-ip-to-cluster didn't work for me even after multiple tries

Closes #ISSUE

Checklist

Before creating a PR, run through this checklist and mark each as complete.

• I have read the CONTRIBUTING doc
• I have added tests that prove my fix is effective or that my feature works
• I have checked that all unit tests pass after adding my changes
• I have updated necessary documentation
• I have rebased my branch onto main
• I will ensure my PR is targeting the main branch and pulling from my branch from my own fork

Release notes

If this PR introduces a change that affects users and needs to be mentioned in the release notes,
please add a brief note that summarizes the change.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 87.02%. Comparing base (ac2cfc6) to head (a66754c).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3802      +/-   ##
==========================================
+ Coverage   86.99%   87.02%   +0.02%     
==========================================
  Files         128      128              
  Lines       16404    16404              
  Branches       62       62              
==========================================
+ Hits        14271    14275       +4     
+ Misses       1957     1954       -3     
+ Partials      176      175       -1     

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