docs: added warning about java formatter requiring Java 11

docs/howtos/development/setup-pre-commit-hooks.md

@@ -144,6 +144,16 @@ pre-commit. This allows you to review the changes and commit any updates to cont
 To run locally, the current `v1.2.0` version of the pre-commit formatter requires Java 11 in your
 path.
 
+!!! warning
+    Minor differences in Java source formatting have been seen when running the
+    `google-java-format` pre-commit hook locally with Java versions > 11 compared to the results
+    when the hook runs as part of a GitLab pipeline (which is currently running the formatter with
+    Java 11). To avoid inconsistencies it is recommended that you **must** run the formatter with
+    Java 11 in your path.
+
+    If your Java project requires a different version of Java to compile, you can use
+    [sdkman](https://sdkman.io/) to easily switch between different versions at your command line.
+
 #### Configuring Git to ignore bulk formatting commits
 
 Adding the