Update docs/source/library-user-guide/upgrading/54.0.0.md

Co-authored-by: Bruce Ritchie <bruce.ritchie@veeva.com>

Author: timsaucer

docs/source/library-user-guide/upgrading/54.0.0.md

@@ -125,7 +125,7 @@ stats.column_statistics[0].min_value = ...;
 
 ### Remove `as_any` from `ScalarUDFImpl`
 
-Now that we have a more recent minimum version of Rust, we can take advantage of
+Now that the MSRV has reached 1.86 we can take advantage of
 trait upcasting for Scalar UDFs. This reduces the amount of boilerplate code that
 users need to do to create a UDF. In your implementations, you can simply remove
 this function. The below diff is an example from the associated PR