Python: fixes for new MCP types and small openapi fix

[eavanvalkenburg]

Motivation and Context

Fixes to include AudioContent for MCP
Small typing improvement in OpenAPI.

Description

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
connectors
mcp.py	392	191	51%	75, 87, 95–100, 102–103, 108, 120–127, 135–139, 141–142, 144, 151–153, 240–242, 257–258, 261–262, 274–275, 279–280, 282, 284, 286–292, 296–298, 300–310, 314–315, 319–320, 324, 326, 330–331, 335, 349, 364–372, 378–379, 381–382, 385–386, 392–393, 413–414, 417–418, 421–426, 430–431, 434–435, 438–444, 453–455, 535, 537, 604, 606, 608, 610, 679, 681, 683, 685, 687, 745, 788–793, 795–798, 803, 856, 858, 861, 874, 894–896, 903–908, 911–913, 916, 918, 922–923, 925, 928–929, 938–939, 941–943, 957–958, 960–961, 963–965, 968, 975–978, 986, 991–996, 1001, 1003, 1006–1009
connectors/openapi_plugin
openapi_parser.py	121	7	94%	61, 118, 182, 244–245, 248–249
TOTAL	26427	3949	85%

Python Unit Test Overview

Tests	Skipped	Failures	Errors	Time
3630	22 💤	0 ❌	0 🔥	2m 3s ⏱️