ci: publish build artifacts (#3103)
ci: publish build artifacts (#3103)

* ci: publish build artifacts (per-commit Caddy binaries)

* ci: include OS name in artifact name of *nix binaries so they don't overwrite each other

mholt/caddy,l3dlp/caddy,l3dlp/caddy,abiosoft/caddy,l3dlp/caddy,abiosoft/caddy,mholt/caddy