(sdk-dart): pub.dev compatible with dependency constraint lower bounds

[paydii]

Downgrade analysis failed failed with 3 errors:

MISSING_REQUIRED_ARGUMENT - lib/src/frb_generated.dart/frb_generated.dart:929:12 - The named parameter 'toolCalls' is required, but there's no corresponding argument.
MISSING_REQUIRED_ARGUMENT - lib/src/frb_generated.dart/frb_generated.dart:1238:12 - The named parameter 'toolCalls' is required, but there's no corresponding argument.
NON_ABSTRACT_CLASS_INHERITS_ABSTRACT_MEMBER - lib/src/frb_generated.dart/frb_generated.dart:1727:7 - Missing concrete implementation of 'OndeChatEngine.loadAssignedModel'.

[setoelkahfi]

already gets a prefect score