ci: fix Forgejo release workflow action versions

Switch checkout/setup-java/setup-gradle to node20-compatible action versions for Forgejo runner v3.5.1.

.forgejo/workflows/build_release.yml

@@ -17,12 +17,12 @@ jobs:
     runs-on: forgejo-release
     steps:
       - name: Clone repository
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        uses: actions/checkout@v4 # Forgejo-compatible (node20)
         with:
           fetch-depth: 0
 
       - name: Set up JDK
-        uses: actions/setup-java@be666c2fcd27ec809703dec50e508c2fdc7f6654 # v5.2.0
+        uses: actions/setup-java@v4 # Forgejo-compatible (node20)
         with:
           java-version: 17
           distribution: temurin
@@ -66,7 +66,7 @@ jobs:
           } >> "$GITHUB_OUTPUT"
 
       - name: Set up Gradle
-        uses: gradle/actions/setup-gradle@f29f5a9d7b09a7c6b29859002d29d24e1674c884 # v5
+        uses: gradle/actions/setup-gradle@v4.4.2 # Forgejo-compatible (node20)
 
       - name: Check code format
         run: ./gradlew spotlessCheck
@@ -248,3 +248,4 @@ jobs:
               "${release_api}/assets?name=${encoded_name}" \
               > /dev/null
           done
+