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/remote/inference/ollama/ollama.py

@@ -36,14 +36,14 @@ from llama_stack.apis.inference import (
 from llama_stack.apis.models import Model, ModelType
 from llama_stack.providers.datatypes import ModelsProtocolPrivate
 from llama_stack.providers.utils.inference.model_registry import (
+    ModelRegistryHelper,
     build_model_alias,
     build_model_alias_with_just_provider_model_id,
-    ModelRegistryHelper,
 )
 from llama_stack.providers.utils.inference.openai_compat import (
-    get_sampling_options,
     OpenAICompatCompletionChoice,
     OpenAICompatCompletionResponse,
+    get_sampling_options,
     process_chat_completion_response,
     process_chat_completion_stream_response,
     process_completion_response,