update to Gateway API v0.5.0-rc1

[skriss]

Updates #4560.

[codecov]

Codecov Report

Merging #4562 (80ce8ce) into main (b0fa15d) will not change coverage.
The diff coverage is 80.95%.

@@           Coverage Diff           @@
##             main    #4562   +/-   ##
=======================================
  Coverage   77.00%   77.00%           
=======================================
  Files         140      140           
  Lines       12784    12784           
=======================================
  Hits         9844     9844           
  Misses       2684     2684           
  Partials      256      256           

Impacted Files	Coverage Δ
internal/status/routeconditions.go	17.72% <0.00%> (ø)
internal/dag/gatewayapi_processor.go	95.44% <91.66%> (ø)
internal/dag/cache.go	94.73% <100.00%> (ø)
internal/gatewayapi/helpers.go	100.00% <100.00%> (ø)

[skriss]

• Updated with v0.5.0-rc1
• backed out the ReferencePolicy -> ReferenceGrant changes (although some of the structs that ReferencePolicy uses have been renamed so I accomodated those) since ReferencePolicy is sticking around for one more release, so I'll do a separate PR to support both for 1 release
• will also do the migration to v1beta1 resources in a separate PR.
• will also pin conformance tests to this release, for PR builds, in a separate PR

[sunjayBhatia]

quick read through lgtm so far!

[skriss]

We could merge this now if we want, which would unblock the other 2 PRs that will get Gateway API conformance passing again, but also can wait until v0.5.0 comes out in a week or two - I'm fine either way since the end result will be the same.

[sunjayBhatia]

i'm cool with merging things early to unblock other things on main, assuming the ga release will be pretty close to this, and will come out before we release a new Contour version