refactor(Agent): remove unused parameters

[raphaelchristi]

This PR removes several unused and deprecated parameters to clean up the codebase:

Changes:

• Remove JSON Mode from OpenAI component (redundant functionality)
• Remove Schema (output_schema) from OpenAI component (deprecated)
• Remove Model Kwargs from OpenAI component (unused)
• Remove Output Parser from OpenAI component (non-functional)
• Remove Verbose parameter from agent component (unused)

These changes simplify the components by removing parameters that were either deprecated, redundant, or not being used effectively.

[codspeed-hq[bot]]

CodSpeed Performance Report

Merging #5172 will degrade performances by 27.74%

_{Comparing raphaelchristi:cleanup/agent-parameters (0ea9320) with main (b692ef7)}

Summary

⚡ 2 improvements
❌ 1 regressions
✅ 12 untouched benchmarks

:warning: Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

	Benchmark	main	raphaelchristi:cleanup/agent-parameters	Change
⚡	test_get_and_cache_all_types_dict	1,043.8 µs	848 µs	+23.09%
⚡	test_successful_run_with_input_type_text	329.1 ms	251.8 ms	+30.71%
❌	test_successful_run_with_output_type_any	177.2 ms	245.3 ms	-27.74%

[edwinjosechittilappilly]

When making changes in Agent Component, Please ensure that the changes in providers are tested. Also Ensure the relevant code refactor is proprly handled in two different PR.

I suggest we have a different PR to remove irrelevant variables from Models and another PR to remove them from Agents.

We have seen issues that any changes in the model components should be tested with the agents; hence, I suggest having a separate PR to remove deprecated params from models (especially the ones used in the agents component).