Remove two PR reviewer checklist items (#65290)

remove two reviewer checklist items

Remove FRR and compatibility checks, because the FRR is only for new features and compatibility is impossible to confirm.

.github/PULL_REQUEST_TEMPLATE.md

@@ -48,5 +48,3 @@ Please check that:
 - [ ] It works as expected from a user's perspective.
 - [ ] If this is a pre-GA feature, it is behind a feature toggle.
 - [ ] The docs are updated, and if this is a [notable improvement](https://grafana.com/docs/writers-toolkit/writing-guide/contribute-release-notes/#how-to-determine-if-content-belongs-in-a-whats-new-document), it's added to our [What's New](https://grafana.com/docs/writers-toolkit/writing-guide/contribute-release-notes/) doc.
-- [ ] There are no known compatibility issues with older supported versions of Grafana, or plugins.
-- [ ] It passes the [Hosted Grafana feature readiness review](https://docs.google.com/document/d/1QL9Ly8KnXzpb6ISbg49pTODRO5mhA5tkkfIZVX6pqQU/edit) for observability, scalability, performance, and security.