[Hotfix] Pin versions of GH actions (#10)

* Pin versions of GH actions

* Update dependency submission action version

Author: mariuscoto

.github/workflows/repository-maintenance.yml

@@ -20,14 +20,14 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout sources
-        uses: actions/checkout@v4.2.1
-      - uses: actions/setup-java@v4.4.0
+        uses: actions/checkout@eef61447b9ff4aafe5dcd4e0bbf5d482be7e7871 # v4.2.1
+      - uses: actions/setup-java@b36c23c0d998641eff861008f374ee103c25ac73 # v4.4.0
         name: Setup Java
         with:
           distribution: temurin
           java-version: 17
       - name: Generate and submit dependency graph
-        uses: gradle/actions/dependency-submission@v4.1.0
+        uses: gradle/actions/dependency-submission@017a9effdb900e5b5b2fddfb590a105619dca3c3 # v4.4.2
         with:
           gradle-version: wrapper
           dependency-graph: generate-and-submit