*: 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/test/ktest/BUILD b/metropolis/test/ktest/BUILD
index 38f1f31..cfbce55 100644
--- a/metropolis/test/ktest/BUILD
+++ b/metropolis/test/ktest/BUILD
@@ -4,7 +4,7 @@
 go_library(
     name = "go_default_library",
     srcs = ["main.go"],
-    importpath = "git.monogon.dev/source/nexantic.git/metropolis/test/ktest",
+    importpath = "source.monogon.dev/metropolis/test/ktest",
     visibility = ["//visibility:private"],
     deps = ["//metropolis/test/launch:go_default_library"],
 )