Update release notes

Signed-off-by: Leandro Lucarella <[email protected]>

Author: llucax

RELEASE_NOTES.md

@@ -10,15 +10,20 @@
 
 ### Cookiecutter template
 
-All upgrading should be done via the migration script or regenerating the templates.
+* Branch protection rule **Protect version branches** was updated, please re-import it following the [instructions](https://frequenz-floss.github.io/frequenz-repo-config-python/v0.13/user-guide/start-a-new-project/configure-github/#rulesets).
+
+    > [!IMPORTANT]
+    > For **api** projects make sure to require the **Check proto files with protolint** status check too, which is not included by the provided ruleset by default.
+
+All other upgrading should be done via the migration script or regenerating the templates.
 
 ```bash
 curl -sSL https://raw.githubusercontent.com/frequenz-floss/frequenz-repo-config-python/v0.12/cookiecutter/migrate.py | python3
 ```
 
 But you might still need to adapt your code:
 
-<!-- Here upgrade steps for cookiecutter specifically -->
+* The new workflows will test using Python 3.12 too, if your code is not compatible with it, you might need to fix it, or you can just remove the Python 3.12 from the test matrix if you need a quick fix. For example, the `typing-extension` library is compatible with Python 3.12 from version 4.6.0, so you might need to upgrade it if you are using it.
 
 ## New Features
 
@@ -33,6 +38,18 @@ But you might still need to adapt your code:
     * Major updates and dependencies excluded by the above groups are still managed, but they'll create one PR per dependency, as breakage is expected, so it might need manual intervention.
     * Finally, we group some dependencies that are related to each other, and usually needs to be updated together.
 
+- The GitHub workflows is now split into PRs and CI workflows.
+
+    These new workflows also start using a new reusable `gh-action-nox`, native arm runners and Ubuntu 24.04, as [Ubuntu 20.04 will be removed from GitHub runners by April's 1st][ubuntu-20.04]. Python 3.12 is also added to the test matrix.
+
+    The PR action is more lightweight, and only tests with one matrix (the most widely used), so PRs can be tested more quickly.
+
+    The push workflow does a more intense testing with all matrix combinations. This also runs for the merge queue, so before PRs are actually merged the tests will run for the complete matrix.
+
+[ubuntu-20.04]: https://github.blog/changelog/2025-01-15-github-actions-ubuntu-20-runner-image-brownout-dates-and-other-breaking-changes/
+
+- The Python `Protect version branches` branch protection rule now request review to Copilot by default.
+
 ## Bug Fixes
 
 <!-- Here goes notable bug fixes that are worth a special mention or explanation -->