CI: authenticate Forgejo git dependencies after transfer

[thedancingdeveloper]

Reapply the recorded post-transfer CI credential rewrite for internal Forgejo git dependencies.

[thedancingdeveloper]

Heads-up from the CI-backlog pass: this PR's premise — authenticate CI to the Forgejo git dependencies — is superseded by the decision to migrate off Forgejo to GitHub instead (see #4). The sibling crates (librtbit-upnp-serve, librtbit-lsd) are already migrated and building on GitHub sources.

This PR also carries unrelated source changes (src/http_api_client.rs, src/storage/filesystem/fs.rs, src/torrent_state/live/peer_handler.rs), so it shouldn't just be closed. Suggest rebasing to drop the ci.yml Forgejo-credential change and keeping/reviewing the source edits on their own — or closing if they're stale.

[thedancingdeveloper]

Closing as fully superseded:

• The CI change (authenticate to the Forgejo git dependencies) is obsolete — librtbit was migrated off Forgejo entirely to GitHub sources (ci: migrate internal deps from Forgejo to GitHub (pinned v0.1.0) #5).
• The source changes (the 7 useless_borrows_in_formatting fixes in http_api_client.rs, storage/filesystem/fs.rs, torrent_state/live/peer_handler.rs) are byte-identical to what already landed on main via ci: migrate internal deps from Forgejo to GitHub (pinned v0.1.0) #5.

Nothing left to salvage.