update: Dependabot、Github Actions用設定を修正

.github/dependabot.yml

@@ -7,6 +7,3 @@ updates:
     time: "00:00"
     timezone: Asia/Tokyo
   open-pull-requests-limit: 10
-  labels:
-    - "dependencies"
-    - "automerge"

.github/workflows/maven.yml

@@ -12,6 +12,9 @@ on:
 jobs:
   build:
     runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      pull-requests: write
     steps:
     - uses: actions/checkout@v3
     - name: Set up JDK 8
@@ -21,4 +24,15 @@ jobs:
         java-version: 8
         cache: maven
     - name: Build with Maven
-      run: mvn -B package --file pom.xml
+      run: mvn -B package --file pom.xml
+    - name: Add label
+      uses: actions/github-script@v6
+      if: ${{ github.event_name == 'pull_request' }}
+      with:
+        script: |
+          github.rest.issues.addLabels({
+            issue_number: context.issue.number,
+            owner: context.repo.owner,
+            repo: context.repo.repo,
+            labels: ["automerge"]
+          })