How to manually sign a file using fastlane/match

[eliaSchenker]

After calling sync_code_signing, how do you sign a binary or file that wasn't built using fastlane (for example a dmg, or a binary executable) with match or fastlane?

platform :macos do
    desc "Signs an existing binary"
    lane :sign do
        sync_code_signing(
            type: "developer_id",
            platform: "macos",
        )
        
        // Sign binary at path ./test-binary with certificate
  end
end

Of course a workaround would be to call codesign manually using sh:

sh("codesign -s \"Developer ID Application: ...\" ./test-binary")

Does a fastlane include a utility for something like that? I checked the docs but couldn't find any.