actions: Don't make Python tests run for markdown files

Author: antonsynd

.github/workflows/python-build-tools.yml

@@ -9,11 +9,13 @@ on:
     paths:
       - 'build_tools/**'
       - '.github/workflows/python-build-tools.yml'
+      - '!build_tools/**/*.md'
   pull_request:
     branches: [ "mainline" ]
     paths:
       - 'build_tools/**'
       - '.github/workflows/python-build-tools.yml'
+      - '!build_tools/**/*.md'
 
 jobs:
   test: