generate-license-file: Move script to scripts folder

This commit also adds if condition to check license file change.
It is to avoid empty commits.

Signed-off-by: Abner C. Paula <abner.cordeiro@ossystems.com.br>

.github/workflows/update-license-file.yml

@@ -19,15 +19,17 @@ jobs:
 
       - name: Run license generation script
         run: |
-          chmod +x ./generate-license-file.sh
-          ./generate-license-file.sh
+          ./scripts/generate-license-file
 
       - name: Commit and push LICENSE file
         run: |
           git config --local user.name "github-actions[bot]"
           git config --local user.email "github-actions[bot]@users.noreply.github.com"
           git add LICENSE
-          git commit -m "Auto-update LICENSE file with current recipe licenses"
-          git push
+          if ! git diff-index --quiet HEAD; then
+            git commit -m "Auto-update LICENSE file with current recipe licenses"
+            git push
+          fi
+
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}