As explained in https://git-scm.com/docs/git-config#Documentation/git-config.txt-branchltnamegtremote
if you have `remote.pushDefault` set in your global gitconfig (like I
do), then _that_ setting will take precedence over
`branch.<name>.remote` 😞
However, `branch.<name>.pushRemote` will take precedence over your
`remote.pushDefault` setting, such that
`gh pr checkout 123 && make changes && git push` will just work, even if
you have `remote.pushDefault` set 💪