Let the PR checks fail

continue-on-error came with the upstream template: lint, test and build had
been red here since January while every pull request read as passing.
fail-fast: false keeps each step running to the end when another fails.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

.github/workflows/pr-any.yml

@@ -3,8 +3,8 @@ on: [pull_request]
 
 jobs:
   pr:
-    continue-on-error: true
     strategy:
+      fail-fast: false
       matrix:
         step: ['lint', 'test', 'build', 'docs']
     runs-on: ubuntu-latest