Python: fix class type

[yanzhang100]

Motivation and Context

It should be "ChatMessageContent" type instead of "FunctionCallContent" type.

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 :smile:

[yanzhang100]

@microsoft-github-policy-service agree [company="{your company}"]

@microsoft-github-policy-service agree company="Microsoft"

[markwallace-microsoft]

Python 3.10 Test Coverage Report •

File	Stmts	Miss	Cover	Missing
TOTAL	5692	904	84%

report-only-changed-files is enabled. No files were changed during this commit :)

Python 3.10 Unit Test Overview

Tests	Skipped	Failures	Errors	Time
1288	1 :zzz:	0 :x:	0 :fire:	13.916s :stopwatch:

[moonbox3]

@yanzhang100 can you please fix the formatting (Ruff) error and push the code upstream? Thanks.

[yanzhang100]

@yanzhang100 can you please fix the formatting (Ruff) error and push the code upstream? Thanks. Fixed the formatting issue. But it shows another issue - Failed Python Test Coverage. Would you please suggest how to fix this? @moonbox3