Automate Browserlist DB Update (openedx#615)

* feat: added cron github action to auto update brwoserlist DB periodically

* refactor: used a shared script to update broswerslist DB, create PR and automerge it

Author: abdullahwaheed

.github/workflows/update-browserslist-db.yml

@@ -0,0 +1,12 @@
+name: Update Browserslist DB
+on:
+  schedule:
+    - cron:  '0 0 * * 1'
+  workflow_dispatch:
+
+jobs:
+  update-browserslist:
+    uses: openedx/.github/.github/workflows/update-browserslist-db.yml@master
+
+    secrets:
+        requirements_bot_github_token: ${{ secrets.requirements_bot_github_token }}