fix: remove stateful instance caching from endpoints for thread-safety

[Copilot]

GenericListGetEndpoint held a self._cache dict mutated on every list() call, creating race conditions and cross-request data leaks when the SDK is shared across threads (FastAPI, Airflow workers, etc.).

Changes

Removed caching infrastructure

• self._cache, _get_local_cache(), _update_local_cache(), _check_cache_hit() deleted from GenericListGetEndpoint
• _enable_cache class attribute removed from EndpointABC and EndpointProtocol
• refresh parameter removed from _list_sync, _list_async, _prepare_list_request, and ListEndpointProtocol
• cache, cached_result, has_filters fields removed from ListRequestState

Endpoint cleanup

• _enable_cache = True removed from StudiesEndpoint, FormsEndpoint, VariablesEndpoint, IntervalsEndpoint

Downstream callers updated

• FilterGetOperation.execute_sync/execute_async: dropped refresh=True from list calls
• validation/cache.py (SchemaValidator, AsyncSchemaValidator, SchemaCache): dropped refresh=True from all variables.list() / variables.async_list() calls

Docs

• docs/caching.rst: replaces the "Endpoint Caches" section with a note that endpoint caching has been removed; directs consumers to application-layer solutions (cachetools, httpx-cache, framework caches)

Every list() / async_list() call now performs a fresh HTTP request. Callers that relied on refresh=True to bypass the cache simply pass no refresh argument.

[fderuiter]

@copilot Job 76252924590 is failing in the Quality & Security job, specifically the Enforce Style step in .github/workflows/main.yml.

Failure:

would reformat tests/unit/test_core_endpoint_operations.py

Oh no! 💥 💔 💥
1 file would be reformatted, 311 files would be left unchanged.

The workflow runs:

poetry run black --check .
poetry run isort --check --profile black .

So the issue is not a test failure; it is a Black formatting failure in:

tests/unit/test_core_endpoint_operations.py

The likely offending line is this long assertion near the end of the file:

client.post.assert_called_once_with(
    "/create", json=[{"field1": "val1"}], headers={HEADER_EMAIL_NOTIFY: "user@example.com"}
)

Black would reformat it to:

client.post.assert_called_once_with(
    "/create",
    json=[{"field1": "val1"}],
    headers={HEADER_EMAIL_NOTIFY: "user@example.com"},
)

Apply that change in tests/unit/test_core_endpoint_operations.py.

You can also let Black fix it automatically:

poetry run black tests/unit/test_core_endpoint_operations.py

Then verify locally with:

poetry run black --check .
poetry run isort --check --profile black .

No workflow change is needed; the job is correctly enforcing formatting.

[Copilot]

@copilot Job 76252924590 is failing in the Quality & Security job, specifically the Enforce Style step in .github/workflows/main.yml.

Failure:
...

Fixed in 69ac685. Black collapsed the two short assert_called_once_with calls from multi-line to single-line form, and expanded the long client.post.assert_called_once_with(...) call into the trailing-comma style it requires.