Python: Pass through arguments when creating agents from specs

[moonbox3]

Motivation and Context

Currently, attempting to pass through KernelArguments through agent creation via declarative spec isn't working properly. The arguments are used to normalize fields, but are then not passed through fully to where the agent is created.

Description

Pass arguments through, and merge them properly with the normalized fields. This allows for underlying args to be used by the agent, like in the case of structured outputs.

• Closes Python: Bug: Declarative agent creation doesn't pass args through #12770

Contribution Checklist

• The code builds clean without any errors or warnings
• The PR follows the SK Contribution Guidelines and the pre-submission formatting script raises no violations
• All unit tests pass, and I have added new tests where possible
• I didn't break anyone 😄

[moonbox3]

Python Test Coverage Report •

File	Stmts	Miss	Cover	Missing
agents/azure_ai
azure_ai_agent.py	362	180	50%	98, 100–103, 105–107, 109–114, 116, 118, 120–122, 124, 141, 143–146, 148–153, 155, 160–161, 166–169, 174–178, 180–183, 185–191, 196, 198–201, 203–205, 207–210, 212, 214, 224–225, 227–230, 232–233, 238, 240–246, 248, 281, 292–293, 298–299, 302, 307–312, 319–320, 322, 327–328, 339–345, 397, 399, 405, 416, 419, 421, 423, 425, 459, 490–492, 494, 496–497, 499–502, 505–507, 509–510, 513, 516–525, 527, 536–537, 540–542, 544–545, 555–556, 558, 576, 578, 581, 583–584, 586–587, 589, 598–599, 601, 603–606, 609, 611, 614–616, 620, 689, 795, 899, 972
agents/chat_completion
chat_completion_agent.py	230	33	85%	68, 73, 78, 84, 100, 102, 108–112, 170, 173, 183, 191, 194, 196, 205, 231, 250, 252–253, 255–256, 259–261, 263, 265, 267, 415, 512, 589
agents/open_ai
openai_assistant_agent.py	363	71	80%	74, 110–113, 118, 122–123, 156, 173–174, 182–187, 194–195, 198, 203–204, 215–221, 399–400, 407–408, 410–411, 413–414, 416–421, 423, 471–472, 475, 478, 481–490, 492, 502, 526–527, 565, 581, 591, 607, 620, 656, 800, 909, 1016
openai_responses_agent.py	410	104	74%	65, 94, 113–116, 124, 128–129, 161–165, 169, 174, 179, 184, 190, 195–196, 199, 202, 207–212, 217–218, 220–221, 227–230, 236, 238–239, 243–247, 338, 342, 346, 348, 354, 367, 369, 371, 375, 470–471, 478–479, 481–482, 484–485, 487–492, 494, 542–543, 546, 591, 607, 617, 651, 659, 662, 666, 668, 671, 694, 697–701, 711, 751, 776, 787, 878, 998, 1039, 1041, 1115, 1155–1156, 1158–1162, 1181
TOTAL	26693	4592	82%

Python Unit Test Overview

Tests	Skipped	Failures	Errors	Time
3659	22 💤	0 ❌	0 🔥	2m 2s ⏱️