Update README.md

Author: cameroncooke

README.md

@@ -136,14 +136,14 @@ The diagnostic tool is a standalone utility that checks your system configuratio
 
 ```bash
 # Run the diagnostic tool using mise
-mise x npm:xcodebuildmcp@latest -- xcodebuildmcp-diagnostic
+mise x npm:xcodebuildmcp@1.3.1 -- xcodebuildmcp-diagnostic
 ```
 
 #### Using with npx
 
 ```bash
 # Run the diagnostic tool using npx
-npx xcodebuildmcp@latest xcodebuildmcp-diagnostic
+npx xcodebuildmcp@1.3.1 xcodebuildmcp-diagnostic
 ```
 
 The diagnostic tool will output comprehensive information about: