mcp/client: fix typo in changeAndNotify&ReadResource

[cryo-zd]

This PR updates the comments for func changeAndNotify and ReadResource to correct typos and improve clarity.

Motivation and Context

This PR is for fixing two typos in mcp/client.go

How Has This Been Tested?

code diff

Breaking Changes

N/A

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update

Checklist

• I have read the MCP Documentation
• My code follows the repository's style guidelines
• New and existing tests pass locally
• I have added appropriate error handling
• I have added or updated documentation as needed

Additional context

[jba]

Thank you!