Documentation for vcpkg_install_msbuild list two example ports that use it, but those ports no longer do

[aggieNick02]

https://github.com/microsoft/vcpkg/blob/master/docs/maintainers/vcpkg_install_msbuild.md

This documentation lists xalan-c and libimobiledevice at the end as examples of ports that use the command. But neither port uses the command anymore. These examples should be removed and, ideally, a current one added.

[NancyLi1013]

These documents have been updated in vcpkg now via #18838.