Pydantic AI v2.1.0 adds Anthropic web tools and MCP error handling

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Pydantic AI, a Python framework for building type-safe AI agents, released v2.1.0 on June 29, 2026. Key additions include support for Anthropic's _20260209 web tools with server-tool replay — enabling agents to use Anthropic's built-in web-browsing capability — and a bug fix that converts ExceptionGroup-wrapped tool errors into ModelRetry inside MCPToolset, improving resilience when agents use Model Context Protocol (MCP) servers. The release also fixes Anthropic Bedrock token counting, which affects cost tracking for agent runs hosted on AWS Bedrock.