ref(scope): Fix get_client typing

The `Scope.get_client` method is typed as returning `sentry_sdk.client.BaseClient`, but because `sentry_sdk.client` was not imported, the type was resolved as `Any`. This change imports `sentry_sdk.client` to fix the type hints.

sentry_sdk/scope.py

@@ -68,6 +68,7 @@
     from sentry_sdk.tracing import TransactionKwargs
 
     import sentry_sdk
+    import sentry_sdk.client
 
     P = ParamSpec("P")
     R = TypeVar("R")