treewide: add license header and enable haslicense linter

Change-Id: I873a8d4082d75e8f813d8a726a41187eea7a065e
Reviewed-on: https://review.monogon.dev/c/monogon/+/3825
Tested-by: Jenkins CI
Reviewed-by: Leopold Schabel <leo@monogon.tech>
diff --git a/build/analysis/BUILD.bazel b/build/analysis/BUILD.bazel
index 371336a..91a2f20 100644
--- a/build/analysis/BUILD.bazel
+++ b/build/analysis/BUILD.bazel
@@ -92,7 +92,7 @@
     "//build/analysis/noioutil",
     "//build/analysis/importsort",
     "//build/analysis/gofmt",
-    #    "//build/analysis/haslicense", #TODO(tim): Enable when fixed
+    "//build/analysis/haslicense",
 ]
 
 # NOGO_CONFIG_OVERRIDES contains the overrides for nogo to exempt specific files