feat: add Groq models

[orimdominic]

This pull request is related to:

• A bug
• A new feature
• Documentation
• Other (New models in genkitx-groq)

I have checked the following:

• I have read and understood the contribution guidelines and the code of conduct;
• I have added new tests (for bug fixes/features);
• I have added/updated the documentation (for bug fixes / features).

Description:
Based on the information at Groq model deprecations, I added the latest models suggestions to the genkitx-groq plugin from the models gotten from groq-models-api

Current	Deprecation	Replacement
llama-3-8b	2026-08-16	openai/gpt-oss-20b
llama-3-70b	2026-08-16	openai/gpt-oss-20b
llama-guard-3-8b	2025-06-06	openai/gpt-oss-safeguard-20b
llama-3.3-70b-versatile	2026-08-16	openai/gpt-oss-120b or qwen/qwen3.6-27b
llama-3.1-8b-instant	2026-08-16	openai/gpt-oss-20b
meta-llama/llama-4-maverick-17b-128e-instruct	2026-03-09	openai/gpt-oss-120b
meta-llama/llama-4-scout-17b-16e-instruct	2026-07-17	openai/gpt-oss-120b or qwen/qwen3.6-27b
mistral-saba-24b	2025-07-30	qwen/qwen3-32b
gemma2-9b	2025-10-08	openai/gpt-oss-20b
qwen-qwq-32b	2025-07-14	openai/gpt-oss-120b
deepseek-r1-distill-llama-70b	2025-04-14	openai/gpt-oss-120b
allam-2-7b	—	No replacement found

Related issues:
Please, link the related issues that this pull request will resolve here (if any).

[xavidop]

it is now ready in version 0.31.0