chore: add Bump License Year workflows (#21)

Author: arttet

.github/workflows/bump-license-year.yml

@@ -0,0 +1,71 @@
+name: Bump License Year
+
+on:
+  schedule:
+    - cron: '0 0 1 1 *'
+  workflow_dispatch:
+
+permissions:
+  contents: write
+  pull-requests: write
+
+jobs:
+  bump-year:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set the current year
+        run: |
+          echo "CURRENT_YEAR=$(date +'%Y')" >> $GITHUB_ENV
+          echo "BRANCH_NAME=bump-license-year-${CURRENT_YEAR}" >> $GITHUB_ENV
+
+      - name: Configure Git
+        run: |
+          git config --global user.name "github-actions[bot]"
+          git config --global user.email "github-actions[bot]@users.noreply.github.com"
+
+      - name: Update license year
+        run: |
+          OLD_YEAR=$(grep -oP '\d{4}' LICENSE | tail -n 1)
+          if [ "$OLD_YEAR" != "${CURRENT_YEAR}" ]; then
+            sed -i "s/$OLD_YEAR/${CURRENT_YEAR}/g" LICENSE
+          fi
+
+      - name: Check for changes
+        id: changes_check
+        run: |
+          if git diff --quiet; then
+            echo "No changes detected."
+            echo "CHANGES_DETECTED=false" >> $GITHUB_ENV
+          else
+            echo "Changes detected."
+            echo "CHANGES_DETECTED=true" >> $GITHUB_ENV
+
+      - name: Create new branch
+        if: env.CHANGES_DETECTED == 'true'
+        run: |
+          git checkout -b ${BRANCH_NAME}
+
+      - name: Commit changes
+        if: env.CHANGES_DETECTED == 'true'
+        run: |
+          git add LICENSE
+          git commit -m "chore: bump license year to ${CURRENT_YEAR}"
+
+      - name: Push changes
+        if: env.CHANGES_DETECTED == 'true'
+        run: git push --set-upstream origin ${BRANCH_NAME}
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Create Pull Request
+        if: env.CHANGES_DETECTED == 'true'
+        uses: actions/create-pull-request@v7
+        with:
+          token: ${{ secrets.GITHUB_TOKEN }}
+          branch: ${BRANCH_NAME}
+          title: 'chore: bump license year to ${CURRENT_YEAR}'
+          base: main