GHA/checksrc: extend zizmor to Dependabot, set cooldown periods

Closes #19216

.github/dependabot.yml

@@ -8,6 +8,8 @@ updates:
     directory: '/'
     schedule:
       interval: 'monthly'
+    cooldown:
+      default-days: 7
     commit-message:
       prefix: 'GHA:'
 
@@ -17,5 +19,10 @@ updates:
       - '/tests'
     schedule:
       interval: 'monthly'
+    cooldown:
+      default-days: 7
+      semver-major-days: 15
+      semver-minor-days: 7
+      semver-patch-days: 3
     commit-message:
       prefix: 'GHA:'

.github/workflows/checksrc.yml

@@ -135,7 +135,7 @@ jobs:
           GH_TOKEN: '${{ secrets.GITHUB_TOKEN }}'
         run: |
           eval "$(/home/linuxbrew/.linuxbrew/bin/brew shellenv)"
-          zizmor --pedantic .github/workflows/*.yml
+          zizmor --pedantic .github/workflows/*.yml .github/dependabot.yml
 
       - name: 'shellcheck CI'
         run: |