caddyhttp: Address some Go 1.20 features (#6252)

Co-authored-by: Francis Lavoie <lavofr@gmail.com>

cmd/x509rootsfallback.go

@@ -0,0 +1,33 @@
+// Copyright 2015 Matthew Holt and The Caddy Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package caddycmd
+
+import (
+	// For running in minimal environments, this can ease
+	// headaches related to establishing TLS connections.
+	// "Package fallback embeds a set of fallback X.509 trusted
+	// roots in the application by automatically invoking
+	// x509.SetFallbackRoots. This allows the application to
+	// work correctly even if the operating system does not
+	// provide a verifier or system roots pool. ... It's
+	// recommended that only binaries, and not libraries,
+	// import this package. This package must be kept up to
+	// date for security and compatibility reasons."
+	//
+	// This is in its own file only because of conflicts
+	// between gci and goimports when in main.go.
+	// See https://github.com/daixiang0/gci/issues/76
+	_ "golang.org/x/crypto/x509roots/fallback"
+)