m/p/localregistry: init

Adds the localregistry package, which serves Bazel-built container
images via the Docker/OCI V2 registry API.

This will be used to serve test images instead of preseeding them.

Change-Id: I0c2ceb9a83f807c9c87ab03bc1141ca67cc64268
Reviewed-on: https://review.monogon.dev/c/monogon/+/1926
Tested-by: Jenkins CI
Reviewed-by: Leopold Schabel <leo@monogon.tech>
diff --git a/go.mod b/go.mod
index 07f784b..eb2726e 100644
--- a/go.mod
+++ b/go.mod
@@ -243,7 +243,7 @@
 	github.com/dgraph-io/ristretto v0.1.0 // indirect
 	github.com/dimchansky/utfbom v1.1.1 // indirect
 	github.com/dnstap/golang-dnstap v0.4.0 // indirect
-	github.com/docker/distribution v2.8.1+incompatible // indirect
+	github.com/docker/distribution v2.8.1+incompatible
 	github.com/docker/go-events v0.0.0-20190806004212-e31b211e4f1c // indirect
 	github.com/docker/go-units v0.4.0 // indirect
 	github.com/dustin/go-humanize v1.0.0 // indirect
@@ -336,7 +336,7 @@
 	github.com/muesli/reflow v0.0.0-20191128061954-86f094cbed14 // indirect
 	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
 	github.com/mxk/go-flowrate v0.0.0-20140419014527-cca7078d478f // indirect
-	github.com/opencontainers/go-digest v1.0.0 // indirect
+	github.com/opencontainers/go-digest v1.0.0
 	github.com/opencontainers/image-spec v1.0.3-0.20211202183452-c5a74bcca799 // indirect
 	github.com/opencontainers/runtime-spec v1.0.3-0.20211123151946-c2389c3cb60a // indirect
 	github.com/opencontainers/selinux v1.10.1 // indirect