ci: make Python validation authoritative (#5940)

Co-authored-by: Alexandre Teixeira <111787685+alteixeira20@users.noreply.github.com>

.github/workflows/ci.yml

@@ -2,7 +2,7 @@ name: CI
 
 on:
   push:
-    branches: [main]
+    branches: [main, dev]
   pull_request:
 
 # Least privilege: none of the jobs write to the repo.
@@ -103,10 +103,7 @@ jobs:
   python-tests:
     name: Python tests (pytest)
     runs-on: ubuntu-latest
-    # Informational for now: the suite has known flaky / environment-dependent
-    # failures (test isolation + embedding-model assertions). Tracked under the
-    # ROADMAP "fresh install smoke tests" item; make this required once green.
-    continue-on-error: true
+    # Make Python test validation authoritative for the configured scope.
     steps:
       - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0  # v7.0.0
         with: