Fire 'Update Components' workflow on push to main

This results in the automatic rebase of an outstanding PR on merges to
this branch, removing the need of manually firing it.

Signed-off-by: Hidde Beydals <hello@hidde.co>

.github/workflows/update.yml

@@ -4,6 +4,8 @@ on:
   workflow_dispatch:
   schedule:
     - cron: "0 * * * *"
+  push:
+    branches: [main]
 
 jobs:
   update-components: