[3.10] bpo-46185: Fix wrong version ref. in macOS installer ReadMe (GH-30280)

Author: Erlend Egeberg Aasland

Mac/BuildScript/resources/ReadMe.rtf

@@ -20,7 +20,7 @@ This package includes its own private copy of OpenSSL 1.1.1.   The trust certifi
 \f0\i0  command line utility are not used as defaults by the Python 
 \f3 ssl
 \f0  module.  A sample command script is included in 
-\f3 /Applications/Python 3.9
+\f3 /Applications/Python 3.10
 \f0  to install a curated bundle of default root certificates from the third-party 
 \f3 certifi
 \f0  package ({\field{\*\fldinst{HYPERLINK "https://pypi.org/project/certifi/"}}{\fldrslt https://pypi.org/project/certifi/}}).  Double-click on