feat(kuma-cp): validate GatewayAPI with multizone

[jakubdyszkiewicz]

Summary

Provide validation that Gateway API cannot be used with Zone and Global CP.
I validate only GatewayClass, otherwise, it's kind of hard to figure out if Gateway or GatewayRoute is used only with Kuma or not. GatewayClass is the required resource for Kuma Gateway to work anyways.

Issues resolved

Fix #3905

Documentation

There is already docs that you cannot use GatewayAPI with mutlizone

Testing

• Unit tests
• E2E tests
• Manual testing on Universal
• Manual testing on Kubernetes

Backwards compatibility

- [ ] Update UPGRADE.md with any steps users will need to take when upgrading.
- [ ] Add backport-to-stable label if the code follows our backporting policy

Changelog: feat(gateway): release K8s GatewayAPI as preview

[codecov-commenter]

Codecov Report

Merging #4022 (b4a6362) into master (a995bb1) will decrease coverage by 0.02%.
The diff coverage is 30.00%.

@@            Coverage Diff             @@
##           master    #4022      +/-   ##
==========================================
- Coverage   56.05%   56.03%   -0.03%     
==========================================
  Files         919      920       +1     
  Lines       55113    55128      +15     
==========================================
- Hits        30895    30891       -4     
- Misses      21774    21789      +15     
- Partials     2444     2448       +4     

Impacted Files	Coverage Δ
pkg/plugins/runtime/k8s/plugin.go	1.08% <0.00%> (+<0.01%)	⬆️
...ime/k8s/webhooks/gatewayapi_multizone_validator.go	37.50% <37.50%> (ø)
pkg/core/tokens/default_signing_key.go	66.66% <0.00%> (-13.89%)	⬇️
pkg/core/secrets/manager/global_manager.go	39.39% <0.00%> (-3.04%)	⬇️
pkg/core/resources/manager/cache.go	85.71% <0.00%> (-2.60%)	⬇️
pkg/plugins/resources/postgres/store.go	74.68% <0.00%> (-0.43%)	⬇️

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