*: git.monogon.dev -> source.monogon.dev

This implements T882, setting our (virtual) GOPATH to source.monogon.dev
for this repository.

Test Plan: Refactor, CI only.

X-Origin-Diff: phab/D686
GitOrigin-RevId: c5e2309089948ffc3a98e68e2e0e1cbb157d3a36
diff --git a/metropolis/proto/common/BUILD.bazel b/metropolis/proto/common/BUILD.bazel
index a5f7eb0..b451dd4 100644
--- a/metropolis/proto/common/BUILD.bazel
+++ b/metropolis/proto/common/BUILD.bazel
@@ -10,7 +10,7 @@
 
 go_proto_library(
     name = "common_go_proto",
-    importpath = "git.monogon.dev/source/nexantic.git/metropolis/proto/common",
+    importpath = "source.monogon.dev/metropolis/proto/common",
     proto = ":common_proto",
     visibility = ["//metropolis:__subpackages__"],
 )
@@ -18,6 +18,6 @@
 go_library(
     name = "go_default_library",
     embed = [":common_go_proto"],
-    importpath = "git.monogon.dev/source/nexantic.git/metropolis/proto/common",
+    importpath = "source.monogon.dev/metropolis/proto/common",
     visibility = ["//metropolis:__subpackages__"],
 )
diff --git a/metropolis/proto/common/common.proto b/metropolis/proto/common/common.proto
index 4defcbe..cc43918 100644
--- a/metropolis/proto/common/common.proto
+++ b/metropolis/proto/common/common.proto
@@ -16,7 +16,7 @@
 
 syntax = "proto3";
 package metropolis.proto.common;
-option go_package = "git.monogon.dev/source/nexantic.git/metropolis/proto/common";
+option go_package = "source.monogon.dev/metropolis/proto/common";
 
 enum TrustBackend {
     DUMMY = 0;