Clean metadata in overlays repo for recently downgraded to community support plugins.

• Check that support level is correctly set to `community` for these plugins and packages
• Replace `dynamicArtifact`s with [oci://ghcr.io] references

List of community plugins in 1.9: [^community-wrappers.txt] (see issue to remove wrappers from RHDH RHIDP-10847).
You can use this PR https://github.com/redhat-developer/rhdh/pull/3960/files to confirm and also Ben's sheet

Community support has been updated in this PR: https://github.com/redhat-developer/rhdh-plugin-export-overlays/pull/1678. 

Before migration:

  dynamicArtifact: ./dynamic-plugins/dist/backstage-community-plugin-quay

After migration for community CI, e.g for a plugin called red-hat-developer-hub-backstage-plugin-scorecard

  dynamicArtifact: oci://ghcr.io/redhat-developer/rhdh-plugin-export-overlays/red-hat-developer-hub-backstage-plugin-scorecard:bs_1.42.5__1.0.0!red-hat-developer-hub-backstage-plugin-scorecard

Important notes:

• The addendum of the !<plugin-name> suffix is going away in RHIDP-8960
• For 1.9, we must use bs_1.45.x__plugin.version for oci references, check out packages for overlays, from 1.9 branch once its created.
• dynamic-plugins.default.yaml is now generated automatically from overlays, so we just need to update dynamicArtifacts in overlays, no changes to dynamic-plugins.default.yaml are needed - sync script will be run to sync the files