CI: Run 'test' workflow as part of the 'deploy-branch' workflow

Mimics the behaviour of the 'deploy-release' workflow, even though branch deployment doesn't depend on Pico's tests to succeed. Pull requests still use the 'test' workflow directly.

.github/workflows/deploy-branch.yml

@@ -12,6 +12,10 @@ env:
     CI_TOOLS_SETUP: https://raw.githubusercontent.com/picocms/ci-tools/master/setup.sh
 
 jobs:
+    test:
+        name: Test Pico CMS
+        uses: ./.github/workflows/test.yml
+
     website:
         name: Update website for branch updates
 

.github/workflows/test.yml

@@ -1,8 +1,6 @@
 name: Test Pico CMS
 
 on:
-    push:
-        branches: [ 'master' ]
     pull_request: {}
     workflow_call: {}