ci: Run build workflow on test branches

As a workaround for CI not running on uploaded builds, allow pushes to
'test*' branches to invoke CI as well.

Signed-off-by: David Brown <[email protected]>

Author: d3zd3z

.github/workflows/build.yml

@@ -10,6 +10,7 @@ on:
     branches:
       - main
       - v*-branch
+      - test*
   pull_request:
     branches:
       - main