Respecting `auto-revert-remote-files` in `forge-bug-reference-setup`

[bramadams]

Fixes a similar issue as https://github.com/magit/magit/issues/5222, where, when using tramp, forge would do substantial unnecessary work inside forge-bug-reference-setup, slowing down the connection or even hanging.

To fix this issue, changes similar to the original magit commit (see https://github.com/magit/magit/commit/61c051ea1cda5fe6c9404cb5ae228088d2e254f0) could easily be repeated, basically shortening out the unless within forge-bug-reference-setup.