Release Plan update for Sync26 - #225

[P-022] release-plan.yaml was changed alongside 1 other file(s)%3A .github/workflows/spectral-oas-caller.yml. release-plan.yaml changes should be submitted in a dedicated PR so that any new validation findings remain clearly attributable to the release-plan change. | Suggestion%3A Split this PR%3A keep release-plan.yaml changes in a dedicated PR, and move the other listed files to a separate PR.