devel/uv: Search in LOCALBASE for config files

[michaelo]

Summary

uv searches by default in /etc for config files, replace with LOCALBASE.

Approved by: yuri (maintainer)

[michaelo]

truss output:

root@135-release-amd64-default-head:/usr/ports/devel/uv # grep /usr/local/etc --color out
read(3,"includedir /usr/local/etc/libmap"...,35) = 35 (0x23)
open("/usr/local/etc/libmap.d",O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC,0165) ERR#2 'No such file or directory'
fstatat(AT_FDCWD,"/usr/local/etc/xdg/uv/uv.toml",0x348e6c167210,0x0) ERR#2 'No such file or directory'
fstatat(AT_FDCWD,"/usr/local/etc/uv/uv.toml",0x348e6c167210,0x0) ERR#2 'No such file or directory'
root@135-release-amd64-default-head:/usr/ports/devel/uv #

[yuri]

Approved.

Thanks,
Yuri