chore: use public repository metadata

[Soengkit]

Summary

• update the package repository metadata to use the public HTTPS GitHub URL
• keep the change limited to package metadata

Validation

• node package metadata assertion
• git diff --check
• git ls-remote https://github.com/biggora/express-useragent.git HEAD
• npm pack --dry-run --ignore-scripts --json passed

[nahremenkova1]

Reviewed the metadata-only diff. The change replaces the deprecated git:// repository URL with git+https://github.com/biggora/express-useragent.git, which is valid npm package metadata and points at the public repository. Local validation passed: repository metadata assertion, git diff --check, git ls-remote against the HTTPS URL, and npm pack --dry-run --ignore-scripts --json.