[ci] Avoid caching missed dependencies

When a dependency is not available, maven creates a file
with extension .lastUpdated. When such a file is present
maven usually doesn't check again for updates (unless -U is used).

.github/workflows/build.yml

@@ -48,6 +48,8 @@ jobs:
           ~/.cache
           ~/work/pmd/target/repositories
           vendor/bundle
+          # avoid caching missed dependencies
+          !~/.m2/repository/**/*.lastUpdated
         key: v3-${{ runner.os }}-${{ hashFiles('**/pom.xml') }}
         restore-keys: |
           v3-${{ runner.os }}-