Add NFR scale test to GitHub actions pipeline

[pleshakov]

Proposed changes

Problem:
Scale test is not part of Github actions pipeline

Solution:

• Add NFR scale test to GitHub actions pipeline along other NFR tests.
• Increase the size of the cluster used for NFR tests, as the scale test requires bigger size.

Testing:

• Successfully run with NGINX -- NFR Test Results for NGF version edge #2002
• Successfully run with NGINX Plus -- NFR Test Results for NGF version edge (Plus) #2017

Some scale test issues were discovered:

• Scale upstreams tests reports errors because zone size for NGINX Plus upstream #2023
• NFR Scale test doesn't count all reloads and batches #2009

Closes #1927

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.

NONE