Add fetch-depth: 0 to check-format checkout for spotless ratchet

The spotless maven plugin uses git ratchet mode to compare against
origin/master. With checkout@v6's default shallow clone, origin/master
is not available, causing the format check to fail.

Adding fetch-depth: 0 to the check-format job ensures the full git
history is cloned including origin/master reference.

Author: salmanmkc

.github/workflows/build.yml

@@ -26,6 +26,8 @@ jobs:
           java-version: '17'
       - name: Checkout repository
         uses: actions/checkout@v6
+        with:
+          fetch-depth: 0
       - name: Build project
         run: |
           gcc --version