feat: Support GigaChat LLM from Langchain

[Rai220]

Adds support of gigachat LLM, that already supported in langchain: https://python.langchain.com/docs/integrations/chat/gigachat/

[codspeed-hq]

CodSpeed Performance Report

Merging #5621 will degrade performances by 36.15%

_{Comparing Rai220:main (8e2f65b) with main (18acd30)}

Summary

⚡ 1 improvements
❌ 1 regressions
✅ 13 untouched benchmarks

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

Benchmarks breakdown

	Benchmark	main	Rai220:main	Change
❌	test_get_and_cache_all_types_dict	1.2 ms	1.9 ms	-36.15%
⚡	test_successful_run_with_output_type_any	281.4 ms	241.3 ms	+16.63%

[Rai220]

Hey @ogabrielluiz ! Could you please review my PR when you have a moment? 🙏 Thanks in advance!