Increase deprecation levels

[devcrocod]

• increase deprecation level for SSEClientTransport and SSEServerTransport from warning to error
• remove old deprecation fun MCP
• update samples to use new fun createSession instead of deprecated one

Motivation and Context

cleanup code and deprecation cycle

Breaking Changes

None

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

[Copilot]

Pull Request Overview

This PR advances the deprecation cycle by increasing the deprecation level for SSE transport type aliases from WARNING to ERROR, removing a fully deprecated function, and updating sample code to use the new API.

• Increased deprecation level for SSEClientTransport and SSEServerTransport type aliases from WARNING to ERROR
• Removed the deprecated MCP function that had already reached ERROR deprecation level
• Updated sample code to use createSession instead of the deprecated connect method

Reviewed Changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
kotlin-sdk-client/src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/client/SSEClientTransport.kt	Increased deprecation level to ERROR for SSEClientTransport type alias
kotlin-sdk-server/src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/server/SSEServerTransport.kt	Increased deprecation level to ERROR for SSEServerTransport type alias
kotlin-sdk-server/src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/server/KtorServer.kt	Removed deprecated MCP function
kotlin-sdk-server/api/kotlin-sdk-server.api	Updated API signature file to reflect removal of MCP function
samples/weather-stdio-server/src/main/kotlin/io/modelcontextprotocol/sample/server/McpWeatherServer.kt	Updated to use createSession instead of connect
samples/kotlin-mcp-server/src/main/kotlin/io/modelcontextprotocol/sample/server/server.kt	Updated to use createSession instead of connect in both SSE and stdio examples

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[kpavlov]

👍