feat(caddy): upgrade to Caddy 2.9.0

[dunglas]

Upgrade to Caddy 2.9 and leverage the new first_exist_fallback try policy (caddyserver/caddy#6699).

[AlliBalliBaba]

@dunglas I noticed that this block will also cause a file access on every request even though its only purpose is to redirect on directory index files from /path -> /path/ (the 'canonical' path). Not sure how to optimize this, but it would be another opportunity to minimize file access.

frankenphp/caddy/caddy.go

Lines 559 to 582 in c2ca4db

	if dirRedir {
	redirMatcherSet := caddy.ModuleMap{
	"file": h.JSON(fileserver.MatchFile{
	TryFiles: []string{dirIndex},
	}),
	"not": h.JSON(caddyhttp.MatchNot{
	MatcherSetsRaw: []caddy.ModuleMap{
	{
	"path": h.JSON(caddyhttp.MatchPath{"*/"}),
	},
	},
	}),
	}
	redirHandler := caddyhttp.StaticResponse{
	StatusCode: caddyhttp.WeakString(strconv.Itoa(http.StatusPermanentRedirect)),
	Headers: http.Header{"Location": []string{"{http.request.orig_uri.path}/"}},
	}
	redirRoute := caddyhttp.Route{
	MatcherSetsRaw: []caddy.ModuleMap{redirMatcherSet},
	HandlersRaw: []json.RawMessage{caddyconfig.JSONModuleObject(redirHandler, "handler", "static_response", nil)},
	}
	routes = append(routes, redirRoute)
	}

[dunglas]

Yes, I already discussed this one with @francislavoie but I'm not sure we can find a generic solution to prevent it.

The best we can do is probably some custom config like this one, or to introduce a cache. https://github.com/dunglas/symfony-docker/blob/main/frankenphp/Caddyfile