feat: allow to pass mailprovider as a workflow input

.github/workflows/cron-storage-limits.yaml

@@ -7,6 +7,13 @@ on:
   # Including 'workflow_dispatch' here allows the job to be triggered manually,
   # as well as on the schedule.
   workflow_dispatch:
+    inputs:
+      email_provider:
+        type: choice
+        description: The mail provider used to send emails to users. Use 'dummy' if you want only to log emails to the console. If not specified the default mail provider is used in prod and the dummy one is used in staging.
+        options: 
+          - mailchimp
+          - dummy
 
 jobs:
   send-notifications:
@@ -42,6 +49,6 @@ jobs:
           PROD_PG_REST_URL: ${{ secrets.PROD_PG_REST_URL }}
           STAGING_PG_REST_URL: ${{ secrets.STAGING_PG_REST_URL }}
           MAILCHIMP_API_KEY: ${{ secrets.MAILCHIMP_API_KEY }}
-          EMAIL_PROVIDER: ${{ (matrix.env == 'staging' && 'dummy') || '' }} # use dummy provider in staging, while using the default provider in prod.
+          EMAIL_PROVIDER: ${{ github.event.inputs.env || ((matrix.env == 'staging' && 'dummy') || '') }} # use dummy provider in staging, while using the default provider in prod.
         run: npm run start:storage -w packages/cron