Cannot read configuration file at "$XDG_CONFIG_HOME/git/config"

[openjck]

Describe the feature or problem you’d like to solve

This snap can't open the Git configuration file if it is at $XDG_CONFIG_HOME/git/config, which is a valid alternative location which the Git client itself supports.

$ echo $XDG_CONFIG_HOME
/home/openjck/.config
$ gh pr checkout 100
warning: unable to access '/home/openjck/.config/git/config': Permission denied
warning: unable to access '/home/openjck/.config/git/config': Permission denied
fatal: unknown error occurred while reading the configuration files
/snap/gh/356/usr/bin/git: exit status 128

Proposed solution

Give the Snap access to read all files in $XDG_CONFIG_HOME/git.