Add self-trigger path for docs workflow

Include .github/workflows/docs.yaml in both push and
pull_request path filters so changes to the workflow
file itself trigger a CI run.

Addresses review feedback from chrishavlin.

Author: mithr4ndir

.github/workflows/docs.yaml

@@ -6,10 +6,12 @@ on:
       - main
     paths:
       - "doc/**"
+      - ".github/workflows/docs.yaml"
       - "pyproject.toml"
   pull_request:
     paths:
       - "doc/**"
+      - ".github/workflows/docs.yaml"
   workflow_dispatch:
 
 permissions: {}