Tags: enable uploading tags created by others to a project owner

This is required by our mirroring scripts at least for the `github/` namespace. It shouldn't hurt to add this globally; our owners are usually bots, anyway.

Change-Id: Ic6136e749b87c0a8b8e36070282488b3f5ad9b82
diff --git a/project.config b/project.config
index 11e02a4..846149e 100644
--- a/project.config
+++ b/project.config
@@ -46,6 +46,8 @@
 	create = group Project Owners
 	createTag = group Project Owners
 	createSignedTag = group Project Owners
+	forgeAuthor = group Project Owners
+	forgeCommitter = group Project Owners
 [label "Code-Review"]
 	function = MaxWithBlock
 	defaultValue = 0