Investigate "subsystem maintainers" as an option

[jamietanna]

i.e. https://github.com/ghostty-org/ghostty/blob/7daabdddef7c0993df4bf13be2c11bd0723e47cf/CODEOWNERS#L5-L10 with the intent that we'd have i.e. a "Gin maintainer" who'd be able to manage the Gin middleware, but also any key Gin-specific code in oapi-codegen