SONARJAVA-6254 Use mise to install mvn in PrepareNextIteration.yml (#5571)

Co-authored-by: Dorian Burihabwa <75226315+dorian-burihabwa-sonarsource@users.noreply.github.com>
Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: tomasz-tylenda-sonarsource <tomasz-tylenda-sonarsource@users.noreply.github.com>

Author: 3 people

.github/workflows/PrepareNextIteration.yml

@@ -20,6 +20,10 @@ jobs:
       - name: Checkout Sources
         uses: actions/checkout@v4
 
+      - uses: jdx/mise-action@5228313ee0372e111a38da051671ca30fc5a96db # v3.6.3
+        with:
+          version: 2025.7.12
+
       - name: Normalize Version
         id: version
         env: