Insert agent instructions after system_prompts for models that don't natively support instructions

[siddhantbhagat8]

• Fixes Instructions being inserted before System Prompt #2423

Description

Changed the insertion logic to insert instructions after all system prompt parts

Simple append:

1. anthropic.py
2. google.py
3. gemini.py
4. bedrock.py

Insert at a particular position:
For models that build a messages list, count SystemPromptPart instances and insert at that index

1. openai.py
2. cohere.py
3. groq.py
4. mistral.py
5. huggingface.py

Testing

I ran the tests locally, everything passed. If I should add a test for this change, please let me know the correct location for the test :)

[DouweM]

@siddhantbhagat8 Thanks Siddhant! Please look at my notes and add a test in test_agent.py, by using both system_prompt and instructions decorators on one agent

[siddhantbhagat8]

@siddhantbhagat8 Thanks Siddhant! Please look at my notes and add a test in test_agent.py, by using both system_prompt and instructions decorators on one agent

I believe I have addressed the core logic feedback as per my understanding :)

[siddhantbhagat8]

@DouweM Sorry for bothering you but would love to get this over the line!

[DouweM]

@siddhantbhagat8 Sorry about the delay, I was at a conference last week and got a bit behind on PR review!

[siddhantbhagat8]

@DouweM Hope you had a great conference!
Sorry for the delay on my part, was slammed with work. I have added the tests for the big 3 (openai, anthropic, and google). Let me know if this is sufficient or if you'd like me to add the tests for the other models as well. More than happy to :)
Ready for your review whenever you get a chance!

[siddhantbhagat8]

I believe the tests are failing due to connection timeouts and not because of the contents of the PR. Let me know if this PR is resulting in the failing tests

[siddhantbhagat8]

@DouweM addressed the feedback!

[DouweM]

@siddhantbhagat8 Thanks Siddhant!

[siddhantbhagat8]

@DouweM thanks for approving and merging!
If I may ask, what release will this change be a part of? And is there any way for me to track it as a contributor?

[DouweM]

@siddhantbhagat8 We release every day, so should be going up in a few hours :)