RELEASING: update after label automation in workflows (#3488)

Author: xrmx

RELEASING.md

@@ -9,7 +9,8 @@
       (otherwise the workflow will pick up the version from `main` and just remove the `.dev` suffix).
   * Review the two pull requests that it creates.
     (one is targeted to the release branch and one is targeted to `main`).
-    * The builds will fail for both the `main` and release pr because of validation rules. Follow the [release workflow](https://github.com/open-telemetry/opentelemetry-python/blob/main/RELEASING.md) for the core repo up until this same point. Change the SHAs of each PR to point at each other to get the `main` and release builds to pass.
+    * The builds will fail for the release PR because of validation rules. Follow the [release workflow](https://github.com/open-telemetry/opentelemetry-python/blob/main/RELEASING.md) for the core repo up until this same point.
+    * Close and reopen the PR so that the workflow will take into account the label automation we have in place
   * Merge the release PR.
   * Merge the PR to main (this can be done separately from [making the release](#making-the-release))