Update s4u/setup-maven-action action to v1.20.0 (#158)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/maven.yml

@@ -10,7 +10,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Setup Maven Action
-      uses: s4u/setup-maven-action@v1.18.0
+      uses: s4u/setup-maven-action@v1.20.0
       with:
         java-version: "${{ matrix.java }}"
     - name: Build with Maven