fix: serialize BaseModel subclasses and avoid calling methods on types

[ogabrielluiz]

This pull request addresses the serialization of BaseModel subclasses by ensuring that type objects are handled separately. The changes prevent type objects from being incorrectly serialized as instances, improving the overall serialization logic. This update enhances the robustness of the serialization process for models derived from BaseModel.

[codspeed-hq]

CodSpeed Performance Report

Merging #4479 will degrade performances by 14.95%

_{Comparing fix-serialization-issubclass (956d9d2) with main (8681c56)}

Summary

⚡ 1 improvements
❌ 3 regressions
✅ 11 untouched benchmarks

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

	Benchmark	main	fix-serialization-issubclass	Change
❌	test_invalid_run_with_input_type_chat	14.8 ms	17.4 ms	-14.95%
❌	test_successful_run_with_input_type_text	449.8 ms	527.2 ms	-14.67%
⚡	test_successful_run_with_output_type_any	453.7 ms	322.8 ms	+40.54%
❌	test_successful_run_with_output_type_debug	451.6 ms	530 ms	-14.78%