Git provides itself, so forges aren’t even required (the d is distributed version control). Issue trackers don’t need to be attached to the code forge. Even if you like someone else hosting it & an sidecar of integrated bug tracking, it should not require an account with Microsoft if privacy is the end goal—and there’s a host (pun not intend) of other options.
PRISM Break, Calyx live on GitLab (not obscure, supports SSO). Many free software projects like Freedesktop, GNOME, KDE, DivestOS, Briar, Jami self-host the community edition of GitLab. Privacy Tools & Awesome Privacy mirror to Codeberg as well as MS GitHub, presumably to have an escape hatch to the megacorporate bubble & to practice what they preach about privacy. LibreWolf is exclusively Codeberg. Cwtch self-hosts Gitea. Prosody self-hosts its Mercurial server. Choosing not Microsoft GitHub puts you in good company.
If a mailing lists alternative isn’t your thing, Forgefed, federation protocol for software forges, would apply for anyone with a Fediverse account (so Lemmy) could submit issues with Forgejo building it in along with others soon (GitLab expressed interest).
Choosing proprietary tools and services for your free software project ultimately sends a message to downstream developers and users of your project that freedom of all users—developers included—is not a priority.