Pin GitHub Actions to full-length commit SHAs

Author: danfiedler-msft

.github/dependabot.yml

@@ -0,0 +1,11 @@
+version: 2
+updates:
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    groups:
+      github-actions:
+        patterns: ["*"]
+    schedule:
+      interval: "weekly"
+    cooldown:
+      default-days: 7

.github/workflows/test.yml

@@ -8,9 +8,9 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@0717577d45739eb3c851188b29f50ed6c0b2194e # v2.8.0
     - name: Set up Python 3.10
-      uses: actions/setup-python@v2
+      uses: actions/setup-python@e9aba2c848f5ebd159c070c61ea2c4e2b122355e # v2.3.4
       with:
         python-version: "3.10"
     - name: Install dependencies