fix: Fix unit tests CI and failing tests (#2928)

# What does this PR do?
<!-- Provide a short summary of what this PR does and why. Link to
relevant issues if applicable. -->
- Added `set -e` to the beginning of the unit test script to ensure the
script exits on failure and correctly fails the CI when tests do not
pass.
- Fixed all unit tests that were silently failing in the CI.
- Fixed Python 3.13 unit test CI failing silently.

<!-- If resolving an issue, uncomment and update the line below -->
<!-- Closes #[issue-number] -->
Closes #2877 

## Test Plan
<!-- Describe the tests you ran to verify your changes with result
summaries. *Provide clear instructions so the plan can be easily
re-executed.* -->
- **Previously:** Unit tests passing in CI eventhough it failed 11 tests
->
[CI-run](4683681501 (step):4:2097)
- **Made the fix. Now, ensuring CI fails as expected on test failures:**
Unit tests failing in CI with 1 failed test ->
[CI-run](4684234247 (step):4:1506)
- This PR shows the CI passing and all unit tests passing.

scripts/unit-tests.sh

@@ -8,6 +8,15 @@
 
 PYTHON_VERSION=${PYTHON_VERSION:-3.12}
 
+set -e
+
+# Always run this at the end, even if something fails
+cleanup() {
+    echo "Generating coverage report..."
+    uv run --python "$PYTHON_VERSION" coverage html -d htmlcov-$PYTHON_VERSION
+}
+trap cleanup EXIT
+
 command -v uv >/dev/null 2>&1 || { echo >&2 "uv is required but it's not installed. Exiting."; exit 1; }
 
 uv python find "$PYTHON_VERSION"
@@ -19,6 +28,3 @@ fi
 # Run unit tests with coverage
 uv run --python "$PYTHON_VERSION" --with-editable . --group unit \
     coverage run --source=llama_stack -m pytest -s -v tests/unit/ "$@"
-
-# Generate HTML coverage report
-uv run --python "$PYTHON_VERSION" coverage html -d htmlcov-$PYTHON_VERSION