pin action checksums, add dependabot

Author: ahoehne

.github/dependabot.yaml

@@ -0,0 +1,12 @@
+version: 2
+updates:
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "monthly"
+    groups:
+      actions:
+        patterns:
+          - "*"
+    open-pull-requests-limit: 3
+

.github/workflows/go-tests.yaml

@@ -24,10 +24,10 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
 
       - name: Set up Go ${{ matrix.go-version }}
-        uses: actions/setup-go@v5
+        uses: actions/setup-go@40f1582b2485089dde7abd97c1529aa768e1baff # v5.6.0
         with:
           go-version: ${{ matrix.go-version }}
           cache: false # cache not needed if there is no go.sum file

.github/workflows/release.yaml

@@ -13,7 +13,7 @@ jobs:
 
     steps:
     - name: Checkout code
-      uses: actions/checkout@v4
+      uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
       with:
         fetch-depth: 0
 
@@ -37,7 +37,7 @@ jobs:
         echo "Tag $GIT_REF_NAME is on main branch"
 
     - name: Set up Go
-      uses: actions/setup-go@v5
+      uses: actions/setup-go@40f1582b2485089dde7abd97c1529aa768e1baff # v5.6.0
       with:
         go-version: '1.26'
         cache: false
@@ -55,7 +55,7 @@ jobs:
         ./build-all.sh "$TAG_NAME"
 
     - name: Create Release
-      uses: softprops/action-gh-release@v2
+      uses: softprops/action-gh-release@a06a81a03ee405af7f2048a818ed3f03bbf83c7b # v2.5.0
       with:
         files: |
           dist/CHECKSUMS.txt

.github/workflows/shellcheck.yml .github/workflows/shellcheck.yaml.github/workflows/shellcheck.yml renamed to .github/workflows/shellcheck.yaml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
 
       - name: Install Shellcheck
         # not needed in gh actions, but when running locally via act