Handle failed DNS case for Go 1.20+

Go 1.20 introduced DNS/CNAME handling changes. This can cause an
IP address represented in hex, oct, etc to be looked up as DNS and
fail. This change introduces a mock DNS resolver.

Note, with the mock resolver, we don't need to use 0x7f000001 any
longer. Keeping because it was already there.

Signed-off-by: Matt Farina <matt.farina@suse.com>

go.mod

@@ -14,6 +14,7 @@ require (
 	github.com/cyphar/filepath-securejoin v0.2.3
 	github.com/distribution/distribution/v3 v3.0.0-20221208165359-362910506bc2
 	github.com/evanphx/json-patch v5.6.0+incompatible
+	github.com/foxcpp/go-mockdns v1.0.0
 	github.com/gobwas/glob v0.2.3
 	github.com/gofrs/flock v0.8.1
 	github.com/gosuri/uitable v0.0.4
@@ -107,6 +108,7 @@ require (
 	github.com/mattn/go-isatty v0.0.17 // indirect
 	github.com/mattn/go-runewidth v0.0.9 // indirect
 	github.com/matttproud/golang_protobuf_extensions v1.0.4 // indirect
+	github.com/miekg/dns v1.1.25 // indirect
 	github.com/mitchellh/go-wordwrap v1.0.0 // indirect
 	github.com/mitchellh/reflectwalk v1.0.2 // indirect
 	github.com/moby/locker v1.0.1 // indirect