Update PHP geoip2 package version to ~3.0

The geoip2/geoip2 PHP package is now at version 3.x. Update the
installation examples to use the latest major version.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <[email protected]>

Author: oschwald

content/geoip/geolocate-an-ip/databases.md

@@ -51,7 +51,7 @@ yarn add @maxmind/geoip2-node
 
 ```php
 # Install via Composer
-composer require geoip2/geoip2:~2.0
+composer require geoip2/geoip2:~3.0
 ```
 
 ```python

content/geoip/geolocate-an-ip/web-services.md

@@ -54,7 +54,7 @@ yarn add @maxmind/geoip2-node
 
 ```php
 # Install via Composer
-composer require geoip2/geoip2:~2.0
+composer require geoip2/geoip2:~3.0
 ```
 
 ```python