chore(ci): unify import aliases and introduce forbidigo

[programmer04]

What this PR does / why we need it:

• unify how k8s.io/* packages are imported (with standardised aliases)
• introduce forbidgo to prevent using old CoreV1 Endpoints

Which issue this PR fixes:

Introducing and configuring fobidgo is a nice to have for issue #3916.

Special notes for your reviewer:

CI will pass after merging PR #3997 that gets rid of CoreV1 Endpoints

PR Readiness Checklist:

Complete these before marking the PR as ready to review:

• the CHANGELOG.md release notes have been updated to reflect any significant (and particularly user-facing) changes introduced by this PR

[pmalek]

🧹

[codecov]

Codecov Report

Patch coverage: 56.1% and project coverage change: +0.1 🎉

Comparison is base (4fa7cf0) 59.7% compared to head (05b3dbf) 59.8%.

❗ Current head 05b3dbf differs from pull request most recent head 3da08a2. Consider uploading reports for the commit 3da08a2 to get more accurate results

Additional details and impacted files

@@           Coverage Diff           @@
##            main   #4016     +/-   ##
=======================================
+ Coverage   59.7%   59.8%   +0.1%     
=======================================
  Files        149     148      -1     
  Lines      16399   16266    -133     
=======================================
- Hits        9793    9731     -62     
+ Misses      5970    5900     -70     
+ Partials     636     635      -1     

Impacted Files	Coverage Δ
...ntrollers/configuration/kongadminapi_controller.go	69.8% <ø> (ø)
...nal/controllers/configuration/secret_controller.go	28.1% <ø> (ø)
...trollers/configuration/zz_generated_controllers.go	27.3% <0.0%> (ø)
internal/controllers/gateway/gateway_controller.go	11.3% <0.0%> (-1.3%)	⬇️
...ternal/controllers/gateway/grpcroute_controller.go	8.8% <0.0%> (ø)
...nternal/controllers/gateway/tcproute_controller.go	8.6% <0.0%> (ø)
...nternal/controllers/gateway/tlsroute_controller.go	8.8% <0.0%> (ø)
...nternal/controllers/gateway/udproute_controller.go	8.6% <0.0%> (ø)
internal/controllers/reference/reference.go	10.2% <0.0%> (ø)
internal/manager/config.go	94.5% <ø> (ø)
... and 14 more

... and 5 files with indirect coverage changes

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