Update reference to Go version (#503)

README.md

diff --git a/README.md b/README.md
index 27c2a14..eb695bd 100644
--- a/README.md
+++ b/README.md
@@ -14,7 +14,7 @@
 
 This library is built in Go, and uses the [support policy](https://golang.org/doc/devel/release.html#policy) of Go as its support policy. The two latest major releases of Go are supported by terraform-exec.
 
-Currently, that means Go **1.18** or later must be used.
+Currently, that means Go **1.22** or later must be used.
 
 ## Usage