chore: bump Gateway API to 0.6.0

[mlavacca]

What this PR does / why we need it:

The Gateway API has been bumped to 0.6.0

Which issue this PR fixes:

Fixes #3214

Special notes for your reviewer:

The Gateway API has been bumped to 0.6.0. A subset of conformance tests has been disabled to keeping this PR as small as possible. In the next iterations, all the currently disabled conformance tests will be fixed and re-enabled.

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

[codecov]

Codecov Report

Base: 73.9% // Head: 74.1% // Increases project coverage by +0.2% 🎉

Coverage data is based on head (c3a2dff) compared to base (1d95681).
Patch coverage: 86.8% of modified lines in pull request are covered.

Additional details and impacted files

@@           Coverage Diff           @@
##            main   #3496     +/-   ##
=======================================
+ Coverage   73.9%   74.1%   +0.2%     
=======================================
  Files        118     118             
  Lines      13987   13886    -101     
=======================================
- Hits       10337   10295     -42     
+ Misses      2989    2939     -50     
+ Partials     661     652      -9     

Impacted Files	Coverage Δ
internal/dataplane/parser/translate_utils.go	88.8% <ø> (ø)
internal/dataplane/parser/wrappers_refchecker.go	64.4% <ø> (+4.7%)	⬆️
internal/util/test/crds.go	70.9% <ø> (-0.5%)	⬇️
...nternal/controllers/gateway/tcproute_controller.go	72.0% <50.0%> (ø)
...nternal/controllers/gateway/tlsroute_controller.go	73.4% <50.0%> (+2.0%)	⬆️
internal/dataplane/parser/translate_tlsroute.go	57.3% <50.0%> (ø)
...nternal/controllers/gateway/udproute_controller.go	73.7% <66.6%> (+2.1%)	⬆️
internal/controllers/gateway/route_utils.go	78.0% <68.9%> (+1.2%)	⬆️
internal/controllers/gateway/gateway_utils.go	90.0% <89.7%> (ø)
internal/controllers/gateway/gateway_controller.go	66.8% <100.0%> (ø)
... and 13 more

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[mlavacca]

Note for the reviewers: a subset of conformance tests has been disabled to keep this PR as small as possible. In the next iterations, all the currently disabled conformance tests will be fixed and re-enabled.