build: format codebase imports using ruff linter (#1028)

# What does this PR do?

- Configured ruff linter to automatically fix import sorting issues.
- Set --exit-non-zero-on-fix to ensure non-zero exit code when fixes are
applied.
- Enabled the 'I' selection to focus on import-related linting rules.
- Ran the linter, and formatted all codebase imports accordingly.
- Removed the black dep from the "dev" group since we use ruff

Signed-off-by: Sébastien Han <seb@redhat.com>

[//]: # (If resolving an issue, uncomment and update the line below)
[//]: # (Closes #[issue-number])

## 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.*]

[//]: # (## Documentation)
[//]: # (- [ ] Added a Changelog entry if the change is significant)

Signed-off-by: Sébastien Han <seb@redhat.com>

llama_stack/providers/tests/vector_io/conftest.py

@@ -11,11 +11,9 @@ from ..conftest import (
     get_provider_fixture_overrides_from_test_config,
     get_test_config_for_api,
 )
-
 from ..inference.fixtures import INFERENCE_FIXTURES
 from .fixtures import VECTOR_IO_FIXTURES
 
-
 DEFAULT_PROVIDER_COMBINATIONS = [
     pytest.param(
         {

llama_stack/providers/tests/vector_io/fixtures.py

@@ -12,7 +12,6 @@ import pytest_asyncio
 
 from llama_stack.apis.models import ModelInput, ModelType
 from llama_stack.distribution.datatypes import Api, Provider
-
 from llama_stack.providers.inline.vector_io.chroma import ChromaInlineImplConfig
 from llama_stack.providers.inline.vector_io.faiss import FaissImplConfig
 from llama_stack.providers.inline.vector_io.sqlite_vec import SQLiteVectorIOConfig

llama_stack/providers/tests/vector_io/test_vector_io.py

@@ -9,10 +9,8 @@ import uuid
 import pytest
 
 from llama_stack.apis.tools import RAGDocument
-
 from llama_stack.apis.vector_dbs import ListVectorDBsResponse, VectorDB
 from llama_stack.apis.vector_io import QueryChunksResponse
-
 from llama_stack.providers.utils.memory.vector_store import make_overlapped_chunks
 
 # How to run this test:

llama_stack/providers/tests/vector_io/test_vector_store.py

@@ -12,8 +12,7 @@ from pathlib import Path
 import pytest
 
 from llama_stack.apis.tools import RAGDocument
-
-from llama_stack.providers.utils.memory.vector_store import content_from_doc, URL
+from llama_stack.providers.utils.memory.vector_store import URL, content_from_doc
 
 DUMMY_PDF_PATH = Path(os.path.abspath(__file__)).parent / "fixtures" / "dummy.pdf"