fix: use interactive sh not bash for whatsapp login

.gitlab-ci.yml

@@ -155,5 +155,5 @@ send-release-notes-to-group:
       - mudslide_cache
   script:
     - mkdir -p mudslide_cache
-    - bash -i "mudslide login"
+    - sh -i "mudslide login"
     - mudslide send $WHATSAPP_RELEASE_NOTIFY_RECIPIENT "$(cat RELEASE_NOTES.md)"