refactor: replace bare dict with dict[str, Any] in dataset and external_knowledge services

[wdeveloper16]

Summary

Tighten bare dict annotations in dataset and external knowledge services:

• services/dataset_service.py — summary_index_setting, data_source_info, estimate_args_validate.args, segment_create_args_validate.args, create_segment.args
• services/external_knowledge_service.py — validate_api_list.api_settings, create_external_knowledge_api.args, check_endpoint_and_api_key.settings, document_create_args_validate.process_parameter, assembling_headers.headers,
  get_external_knowledge_api_settings.settings, create_external_dataset.args, external_retrieval_parameters

All are dynamic API/datasource configurations or parsed request payloads, so dict[str, Any] is the correct shape. Any is already imported in both files.

No behavior change — types only.

Part of #22651.

Test plan

• make lint passes
• make type-check-core passes

[github-actions]

Pyrefly Diff

base → PR

--- /tmp/pyrefly_base.txt	2026-04-13 14:40:38.611394652 +0000
+++ /tmp/pyrefly_pr.txt	2026-04-13 14:40:28.866470621 +0000
@@ -6249,7 +6249,7 @@
    --> tests/unit_tests/services/test_external_dataset_service.py:116:60
 ERROR Argument `str` is not assignable to parameter `type` with type `Literal['api-key', 'no-auth']` in function `services.entities.external_knowledge_entities.external_knowledge_entities.Authorization.__init__` [bad-argument-type]
    --> tests/unit_tests/services/test_external_dataset_service.py:117:35
-ERROR Argument `None` is not assignable to parameter `api_settings` with type `dict[Unknown, Unknown]` in function `services.external_knowledge_service.ExternalDatasetService.validate_api_list` [bad-argument-type]
+ERROR Argument `None` is not assignable to parameter `api_settings` with type `dict[str, Any]` in function `services.external_knowledge_service.ExternalDatasetService.validate_api_list` [bad-argument-type]
    --> tests/unit_tests/services/test_external_dataset_service.py:401:54
 ERROR Argument `str | None` is not assignable to parameter `s` with type `bytearray | bytes | str` in function `json.loads` [bad-argument-type]
    --> tests/unit_tests/services/test_external_dataset_service.py:880:31