GEP: Review HTTP Retries GEP

[kate-osborn]

A/C:

• Review Configurable Retries GEP PR: gep: add GEP-1731 Configurable Retries kubernetes-sigs/gateway-api#3199
• Determine if NGF can support the new API

[kate-osborn]

Reviewed PR and commented that we cannot support the retry API out of the box. Also asked why it's classified as Extended instead of implementation-specific.