feat(connect): include git repo metadata with bundle

[nealrichardson]

The 2025.12.0 Connect release allows including extra metadata fields with bundle uploads, including fields for source control (previously only used by Connect's "git-backed publishing" feature). We should include that metadata from rsconnect when publishing to Connect, if the Connect server version is sufficient (see posit-dev/rsconnect-python#736 for reference).

[nealrichardson]

#1284 was needed to make it easier to add support for multipart form uploads. So this feature will only be implemented for the httr2 HTTP client.