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/inline/scoring/braintrust/braintrust.py

@@ -29,9 +29,7 @@ from llama_stack.apis.scoring import (
     ScoringResultRow,
 )
 from llama_stack.apis.scoring_functions import ScoringFn, ScoringFnParams
-
 from llama_stack.distribution.datatypes import Api
-
 from llama_stack.distribution.request_headers import NeedsRequestProviderData
 from llama_stack.providers.datatypes import ScoringFunctionsProtocolPrivate
 from llama_stack.providers.utils.common.data_schema_validator import (
@@ -39,8 +37,8 @@ from llama_stack.providers.utils.common.data_schema_validator import (
     validate_dataset_schema,
     validate_row_schema,
 )
-
 from llama_stack.providers.utils.scoring.aggregation_utils import aggregate_metrics
+
 from .config import BraintrustScoringConfig
 from .scoring_fn.fn_defs.answer_correctness import answer_correctness_fn_def
 from .scoring_fn.fn_defs.answer_relevancy import answer_relevancy_fn_def

llama_stack/providers/inline/scoring/braintrust/scoring_fn/fn_defs/answer_correctness.py

@@ -11,7 +11,6 @@ from llama_stack.apis.scoring_functions import (
     ScoringFn,
 )
 
-
 answer_correctness_fn_def = ScoringFn(
     identifier="braintrust::answer-correctness",
     description=(

llama_stack/providers/inline/scoring/braintrust/scoring_fn/fn_defs/factuality.py

@@ -11,7 +11,6 @@ from llama_stack.apis.scoring_functions import (
     ScoringFn,
 )
 
-
 factuality_fn_def = ScoringFn(
     identifier="braintrust::factuality",
     description=(