Update workflow to build on PR, and to do a scheduled weekly build.

Author: bleargh45

.github/workflows/perl-ci.yml

@@ -1,7 +1,15 @@
 ---
 name: CI
 
-on: [push]
+on:
+  push:
+    branches:
+      - "*"
+  pull_request:
+    branches:
+      - "*"
+  schedule:
+    - cron: "15 6 * * 0"  # Once weekly, on Sundays
 
 env:
   APACHE_RELEASE: http://archive.apache.org/dist/httpd/httpd-2.4.52.tar.gz