CI: Force pull requests to fetch history (#9720)

Previous implementation only fetched the
latest changes made in the current branch.
Since the CI pipeline only triggers on the
latest pushed commit, this means linting
errors could previously be avoided due to
having multiple commits in a single push.

Author: im-tofa

.github/workflows/test.yml

@@ -21,6 +21,8 @@ jobs:
 
     steps:
     - uses: actions/checkout@v3
+      with:
+        fetch-depth: 100 # assumes PR/push to master is no larger than 100 commits. Other solutions are needlessly complex.
 
     - name: Use Node.js ${{ matrix.node-version }}
       uses: actions/setup-node@v3