update github actions to commits (#24)

Author: rxbchen

.github/dependabot.yaml

@@ -0,0 +1,6 @@
+version: 2
+updates:
+  - package-ecosystem: github-actions
+    directory: "/"
+    schedule:
+      interval: weekly

.github/workflows/test.yml

@@ -16,8 +16,8 @@ jobs:
         os: ["ubuntu-latest", "macos-latest"]
     name: Ruby ${{ matrix.ruby }} on ${{ matrix.os }}
     steps:
-      - uses: actions/checkout@v4
-      - uses: ruby/setup-ruby@v1
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: ruby/setup-ruby@dffc446db9ba5a0c4446edb5bca1c5c473a806c5 # v1.235.0
         with:
           ruby-version: ${{ matrix.ruby }}
           bundler-cache: true