Add a Windows test report workflow.

This should allow highlighting Windows test status during the bring-up
period.

More work towards #2658.

.github/workflows/windows-test-report.yml

@@ -0,0 +1,24 @@
+name: Windows Test Report
+on:
+  workflow_run:
+    workflows:
+      - CI
+    types:
+      - completed
+permissions:
+  contents: read
+  actions: read
+  checks: write
+jobs:
+  report:
+    runs-on: ubuntu-24.04
+    steps:
+    - uses: dorny/test-reporter@v1
+      with:
+        artifact: test-results
+        name: pytest results
+        path: 'dist/reports/tests-*.xml'
+        reporter: java-junit
+        fail-on-error: false
+        fail-on-empty: false
+        working-directory: repo