Changes

chore(ticdc): update presubmit job configurations to modify triggers (#3426)

These two test pipelines have passed testing and can now enable
conditional triggers, requiring tests to be run before merging the PR.

Refactor the latest-presubmits.yaml to introduce a reusable
skip_if_only_changed pattern and update the trigger expressions for the
MySQL integration jobs to allow for 'all' tests. Additionally, set the
optional flag to false for both integration jobs.
 (commit: ff3bfb8)