fix: update service-2.json with latest public botocore service model

[lucasjia-aws]

Issue

This PR updates the bundled service-2.json to the lastest public botocore service model and regenerates all codegen outputs.

Changes

Commit 1: Update service model and regenerate codegen outputs

Area	File(s)	Change
Service model	sagemaker-core/sample/sagemaker/2017-07-24/service-2.json	Replaced with latest public botocore service model
Codegen tooling	tools/constants.py	Added PIPE_VAR_OVERRIDES for ResourceConfig (IntPipeVar), IntPipeVar to type mappings, REQUIRED_TO_OPTIONAL_OVERRIDES for ModelPackage/SecurityConfig, SHAPES_CODEGEN_OUTPUT_DIR
Codegen tooling	tools/resources_extractor.py	Added EXCLUDED_RESOURCES = {"Session"} to prevent codegen name collision with boto3 Session
Codegen tooling	tools/resources_codegen.py	Updated Session import to from boto3.session import Session
Codegen tooling	tools/shapes_codegen.py	Added IntPipeVar import, updated shapes output path to shapes/ directory
Codegen tooling	tools/shapes_extractor.py	Applied PIPE_VAR_OVERRIDES during shape member generation
Codegen output	resources.py	Regenerated from public service model (83 resources)
Codegen output	shapes/shapes.py	Regenerated from public service model
Codegen output	config_schema.py	Regenerated
Codegen output	resource_plan.csv	Regenerated (Session removed)
Codegen output	utils/code_injection/shape_dag.py	Regenerated
Codegen output	tools/api_coverage.json	Regenerated

Commit 2: Fix upstream package compatibility

Area	File(s)	Change
sagemaker-train	finetune_utils.py	Removed enable_ffm param from _create_input_channels() (field no longer in public model)
sagemaker-mlops	feature_group_manager.py	Removed unused AddOnlineStoreReplicaAction import (shape no longer in public model)
sagemaker-mlops	test_iceberg_properties.py	Removed unsupported description param from FeatureGroup update test calls

Testing

• All sagemaker-core unit tests pass
• All sagemaker-train unit tests pass
• All sagemaker-mlops unit tests pass
• All sagemaker-serve unit tests pass
• Integration tests running in CI