Python: Update kernel function span

[TaoChenOSU]

Motivation and Context

Closing #12262

Description

This PR updates tracing support for function execution across both .NET and Python according to the latest OTel GenAI semantic conventions: https://opentelemetry.io/docs/specs/semconv/gen-ai/gen-ai-spans/#execute-tool-span

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 😄

[markwallace-microsoft]

Python Test Coverage Report •

File	Stmts	Miss	Cover	Missing
kernel.py	228	58	74%	148, 159, 163, 313–314, 316, 398, 404–405, 409–410, 463–467, 469–470, 483–492, 494, 496–497, 499–519, 521–526
filters
kernel_filters_extension.py	79	0	100%
filters/auto_function_invocation
auto_function_invocation_context.py	11	0	100%
functions
kernel_function.py	130	0	100%
utils/telemetry/model_diagnostics
function_tracer.py	12	0	100%
gen_ai_attributes.py	31	0	100%
TOTAL	27015	4574	83%

Python Unit Test Overview

Tests	Skipped	Failures	Errors	Time
3616	18 💤	0 ❌	0 🔥	1m 55s ⏱️