Make build jobs weekly

Author: elfiesmelfie

.github/workflows/build.yml .github/workflows/weekly-jobs.yml

@@ -1,11 +1,13 @@
-name: Build
+name: Weekly container builds
 
 on:
+  # These push/pr options will be removed one they are proven to work (one PR/push ought to do it)
+  pull_request:
+    branches: main
   push:
     branches: main
-  # This will eventually be run on a schedule, daily initially, but some might be better weekly.
-  #  schedule:
-  #    - cron: '0 0 * * *'
+  schedule:
+    - cron: '0 0 * * 0'
 
 jobs:
   build:
@@ -22,21 +24,14 @@ jobs:
           - buster_amd64
             # Debian 9
           - stretch_amd64
-            #- stretch_i386
             # Debian 8
           - jessie_amd64
-            #- jessie_i386
-            #- wheezy_i386
           # Ubuntu
             # Ubuntu 16.04
           - xenial_amd64
-            #- xenial_i386
             # Ubuntu 14.04
           - trusty_amd64
-            #- trusty_i386
-          # Red Hat
-          - el8_x86_64
-            #- el7_i386
+          # CentOS
           - el7_x86_64
           # Rolling/unstable
           - sid_amd64