Update Python SIG from gitter to Github Discussion (#639)

README.md

@@ -104,7 +104,7 @@ Java: SDK|Every Friday at 08:00 PDT|[Google Doc](https://docs.google.com/documen
 Java: Instrumentation|Every Thursday at 09:00 PT|[Google Doc](https://docs.google.com/document/d/1WK9h4p55p8ZjPkxO75-ApI9m0wfea6ENZmMoFRvXSCw/edit?usp=sharing)|[Zoom](https://zoom.us/j/8203130519)|[GitHub Discussions](https://github.com/open-telemetry/opentelemetry-java-instrumentation/discussions)|
 JavaScript: SDK|Every Wednesday at 09:00 PT|[Google Doc](https://docs.google.com/document/d/1S_pN7sBU7wO6cBP2hDSAt3bjSWdWdm6jWeUikC9KrcY/edit?usp=sharing)|[Zoom](https://zoom.us/j/8287234601)|[GitHub Discussions](https://github.com/open-telemetry/opentelemetry-node/discussions)|
 PHP: SDK|Every Wednesday at 10:30 PT|[Google Doc](https://docs.google.com/document/d/1WLDZGLY24rk5fRudjdQAcx_u81ZQWCF3zxiNT-sz7DI/edit)|[Zoom](https://zoom.us/j/8287234601)|[Gitter](https://gitter.im/open-telemetry/opentelemetry-php)|
-Python: SDK|Every Thursday at 09:00 PT|[Google Doc](https://docs.google.com/document/d/1CIMGoIOZ-c3-igzbd6_Pnxx1SjAkjwqoYSUWxPY8XIs/edit)|[Zoom](https://zoom.us/j/6729396170)|[Gitter](https://gitter.im/open-telemetry/opentelemetry-python)|
+Python: SDK|Every Thursday at 09:00 PT|[Google Doc](https://docs.google.com/document/d/1CIMGoIOZ-c3-igzbd6_Pnxx1SjAkjwqoYSUWxPY8XIs/edit)|[Zoom](https://zoom.us/j/6729396170)|[GitHub Discussions](https://github.com/open-telemetry/opentelemetry-python/discussions)|
 Ruby: SIG|Every Thursday at 09:00 PT|[Google Doc](https://docs.google.com/document/d/1D15bO8o340sQm2CVZiukEJuCO_XMMHKPuTznoEhyFqE/edit)|[Zoom](https://zoom.us/j/8287234601)|[Gitter](https://gitter.im/open-telemetry/opentelemetry-ruby)|
 Rust: SDK|Every other week on Tuesday alternating between 07:00 and 15:00 PT|[Google Doc](https://docs.google.com/document/d/1tGKuCsSnyT2McDncVJrMgg74_z8V06riWZa0Sr79I_4)|[Zoom](https://zoom.us/j/8203130519)|[Gitter](https://gitter.im/open-telemetry/opentelemetry-rust)|
 Specification: General|Every Tuesday at 08:00 PT|[Google Doc](https://docs.google.com/document/d/1-bCYkN-DWJq4jw1ybaDZYYmx-WAe6HnwfWbkm8d57v8/edit?usp=sharing)|[Zoom](https://zoom.us/j/6729396170)|[Gitter](https://gitter.im/open-telemetry/opentelemetry-specification)