[BUG](test): fix fastapi fixture registration and sqlite_fixture name

Three issues in chromadb/test/conftest.py broke test collection:

fastapi, async_fastapi, and fastapi_persistent were plain functions
without @pytest.fixture decorators. The system fixture uses
request.getfixturevalue() with their names as params, which requires
them to be registered fixtures. Without the decorator pytest raises
'fixture not found' at collection time.

The same three functions used return instead of yield from, so the
server teardown (system.stop() and proc.kill()) inside _fastapi_fixture
never ran after tests completed.

filtered_fixture_names() listed 'sqlite_fixture' which does not exist;
the registered parameterized fixture is named 'sqlite'. Tests
parameterized via the system fixture would skip the sqlite variant
silently.

Fixes: add @pytest.fixture() to the three functions, switch return to
yield from, and rename 'sqlite_fixture' to 'sqlite' in the default
fixture list.

Fixes #7395

Author: rekha-suthar

chromadb/test/conftest.py

@@ -387,19 +387,22 @@ def run(args: Any) -> Generator[System, None, None]:
         yield from run(args)
 
 
+@pytest.fixture()
 def fastapi() -> Generator[System, None, None]:
-    return _fastapi_fixture(is_persistent=False)
+    yield from _fastapi_fixture(is_persistent=False)
 
 
+@pytest.fixture()
 def async_fastapi() -> Generator[System, None, None]:
-    return _fastapi_fixture(
+    yield from _fastapi_fixture(
         is_persistent=False,
         chroma_api_impl="chromadb.api.async_fastapi.AsyncFastAPI",
     )
 
 
+@pytest.fixture()
 def fastapi_persistent() -> Generator[System, None, None]:
-    return _fastapi_fixture(is_persistent=True)
+    yield from _fastapi_fixture(is_persistent=True)
 
 
 def fastapi_ssl() -> Generator[System, None, None]:
@@ -753,7 +756,7 @@ def filtered_fixture_names() -> List[str]:
         "fastapi",
         "async_fastapi",
         "fastapi_persistent",
-        "sqlite_fixture",
+        "sqlite",
         "sqlite_persistent",
     ]