Fix MSRV reference in convex-rs README.md (#32574)

This was bumped with convex-rs 0.9.0.

GitOrigin-RevId: 7d509c2063e7f9eac65d9d8db4be7c85867b120c

Author: goffrie

README.md

@@ -41,7 +41,7 @@ available on [docs.rs](https://docs.rs/convex/latest/convex/)
 
 # MSRV
 
-The Convex rust client works on stable rust 1.65.0 and higher. It also works on
+The Convex rust client works on stable rust 1.71.1 and higher. It also works on
 nightly.
 
 # Debug Logging