Remove unused code

[jjngx]

Proposed changes

This PR removes unused code from the telemetry pkg test.

staticcheck:

➜  kubernetes-ingress git:(main) staticcheck internal/telemetry/*.go
internal/telemetry/collector_test.go:2280:6: func getResourceKey is unused (U1000)

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