Validation Example Configuration tool - fails on missing parameters due to docs PR waiting on code merge #2673

For example, #2672 has a new parameter failing on the validation check as it's looking at the current Fluent Bit code base and not accounting for the waiting code changes at fluent/fluent-bit#12287.

The checker needs to use the code merge branch as the source of truth for validating doc PRs. Attached error message in a pipeline run that was affected.