also pin official github actions

.github/workflows/debian.yml

@@ -44,7 +44,7 @@ jobs:
     env:
       INPUT_PPAVER: ${{ inputs.ppaver }}
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8
       - id: deb-version
         name: Determine deb-version
         run: |
@@ -59,7 +59,7 @@ jobs:
           sudo apt-get update
           sudo apt-get install debhelper devscripts dput coffeelibs-jdk-${{ env.COFFEELIBS_JDK }}=${{ env.COFFEELIBS_JDK_VERSION }}
       - name: Setup Java
-        uses: actions/setup-java@v5
+        uses: actions/setup-java@dded0888837ed1f317902acf8a20df0ad188d165
         with:
           distribution: ${{ env.JAVA_DIST }}
           java-version: ${{ env.JAVA_VERSION }}
@@ -142,7 +142,7 @@ jobs:
         run: |
           gpg --batch --quiet --passphrase-fd 0 --pinentry-mode loopback -u 615D449FE6E6A235 --detach-sign -a cryptomator_*_amd64.deb
       - name: Upload artifacts
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02
         with:
           name: linux-deb-package
           path: |