smalltown -> metropolis

This pass removes all mentions of Smalltown, both from code and comments,
and replaces them with appropriate new terminology.

Test Plan: Refactor, covered by CI.

X-Origin-Diff: phab/D674
GitOrigin-RevId: 04a94d44ef07d46f7821530da5614daefe16d7ea
diff --git a/metropolis/test/nanoswitch/BUILD b/metropolis/test/nanoswitch/BUILD
index fc4f932..7b088f1 100644
--- a/metropolis/test/nanoswitch/BUILD
+++ b/metropolis/test/nanoswitch/BUILD
@@ -1,5 +1,5 @@
 load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
-load("//metropolis/node/build:def.bzl", "smalltown_initramfs")
+load("//metropolis/node/build:def.bzl", "node_initramfs")
 
 go_library(
     name = "go_default_library",
@@ -28,7 +28,7 @@
     visibility = ["//visibility:public"],
 )
 
-smalltown_initramfs(
+node_initramfs(
     name = "initramfs",
     files = {
         ":nanoswitch": "/init",