Add No-Changed-Files submit requirement

Working on Pigweed: http://pwrev.dev/235193

Bug: b/366020813
Change-Id: I52a0b399b944f4c56f4810a4bfcae2c4e6e208da
Reviewed-on: https://bluetooth-review.googlesource.com/c/All-Projects/+/2160
Reviewed-by: Ted Pudlik <tpudlik@google.com>
diff --git a/project.config b/project.config
index dc331ce..7a08d23 100644
--- a/project.config
+++ b/project.config
@@ -97,3 +97,8 @@
 	applicableIf = file:\"^patches\\.json$\"
 	submittableIf = is:false
 	canOverrideInChildProjects = true
+[submit-requirement "No-Changed-Files"]
+	description = This change does not modify any files.
+	applicableIf = -path:\"^.*$\"
+	submittableIf = is:false
+	canOverrideInChildProjects = false