docs: add Mastra to Python integrations table

Author: DABH

docs/develop/python/integrations/index.mdx

@@ -24,6 +24,7 @@ The following integrations are available between the Temporal Python SDK and thi
 | ----------------- | --------------- | ------------------------------------------------------------------ | ------------------------------------------------------------------------------------------------------ |
 | Braintrust        | Observability   | [braintrust.dev](https://braintrust.dev/docs)                      | [Guide](./braintrust.mdx)                                                                              |
 | Google ADK        | Agent framework | [adk.dev](https://adk.dev/)                                        | [Guide](https://adk.dev/integrations/temporal/)                                                        |
+| Mastra            | Agent framework | [mastra.ai](https://mastra.ai/docs)                                | [Guide](https://mastra.ai/guides/deployment/temporal)                                                  |
 | OpenAI Agents SDK | Agent framework | [openai.github.io](https://openai.github.io/openai-agents-python/) | [Guide](https://github.com/temporalio/sdk-python/blob/main/temporalio/contrib/openai_agents/README.md) |
 | Pydantic AI       | Agent framework | [ai.pydantic.dev](https://ai.pydantic.dev/)                        | [Guide](https://ai.pydantic.dev/durable_execution/temporal/)                                           |
 | Tenuo             | Governance      | [tenuo.ai](https://tenuo.ai/docs)                                  | [Guide](https://tenuo.ai/temporal)                                                                     |