Validate that pubrules passes on PRs.

Also adjust editorconfig to indent workflows correctly.

Author: jyasskin

.editorconfig

@@ -9,3 +9,7 @@ indent_size = 4
 end_of_line = lf
 insert_final_newline = true
 trim_trailing_whitespace = true
+
+[*.yml]
+indent_style = space
+indent_size = 2

.github/workflows/build.yml

@@ -11,7 +11,7 @@ jobs:
       contents: write
     steps:
       - uses: actions/checkout@v4
-      - uses: w3c/spec-prod@v2
+      - uses: w3c/spec-prod@pubrules-profiles-patch
         with:
           BUILD_FAIL_ON: warning
           GH_PAGES_BRANCH: gh-pages
@@ -21,3 +21,4 @@ jobs:
             status: NOTE
             metadata order: *, !*
             metadata include: Participate no, Feedback yes
+          VALIDATE_PUBRULES: true