Allow manual workflow runs

Turns out, both CI and CodeQL were disabled due to lack of activity,
so all the recent pushes were not tested. Allow manual runs for such
cases i the future.

.github/workflows/ci.yml

@@ -12,6 +12,8 @@ on:
   # changed dependencies.
   schedule:
     - cron: '17 04 * * 0'
+  # Manual trigger
+  workflow_dispatch:
 
 name: CI
 jobs:

.github/workflows/codeql-analysis.yml

@@ -8,6 +8,8 @@ on:
     branches: [main]
   schedule:
     - cron: '0 5 * * 1'
+  # Manual run:
+  workflow_dispatch:
 
 jobs:
   analyze: