treewide: add gofmt linter

Change-Id: Ic0d8450b46790c4dc797b117634227be9a48de01
Reviewed-on: https://review.monogon.dev/c/monogon/+/3827
Reviewed-by: Leopold Schabel <leo@monogon.tech>
Tested-by: Jenkins CI
diff --git a/build/bazel/go.MODULE.bazel b/build/bazel/go.MODULE.bazel
index ec02cbd..e7f0da3 100644
--- a/build/bazel/go.MODULE.bazel
+++ b/build/bazel/go.MODULE.bazel
@@ -25,6 +25,7 @@
     "com_github_gdamore_tcell_v2",
     "com_github_go_delve_delve",
     "com_github_golang_migrate_migrate_v4",
+    "com_github_golangci_gofmt",
     "com_github_google_cel_go",
     "com_github_google_certificate_transparency_go",
     "com_github_google_go_cmp",