Relative folder path in git config core.sshCommand to specify a repo specific/deploy (ssh) key

I’ve been looking to specify the path to ssh key relative to the git directory.

It usually looks like this in .git/config:

[core]
    sshCommand = ssh -i ~/.ssh/id_rsa_repo -F /dev/null #-vvv #Uncomment -vvv for verbose output.

Can be set by editing the .git/config file or by running:
if another value already exists:
git config --unset core.sshCommand

sshCommand="ssh -i "$SCRIPT_DIR"/../.ssh/id_rsa_repo -F /dev/null"
git config core.sshCommand "$sshCommand"