Update main.yml

Author: pawanjenu

.github/workflows/main.yml

@@ -60,6 +60,7 @@ jobs:
       - name: Release to Mozilla Amo
         if: ${{ github.event_name == 'workflow_dispatch' }}
         run: |
+          npm i web-ext
           cd ./dist/LeetcodeSessionManager
           web-ext sign --api-key ${{ secrets.FIREFOX_API_KEY }} --api-secret ${{ secrets.FIREFOX_API_SECRET }} --channel listed --id ${{ secrets.FIREFOX_API_ID }} || true