Deny host python tools

So that the host ones don't become available when we remove the
checked-in python2.

Bug: 203436762
Test: Presubmits
Change-Id: Ib8d7b2d73eb2dea7d15a482282692e85397b99e6
diff --git a/ui/build/paths/config.go b/ui/build/paths/config.go
index 6c9a1eb..110ddee 100644
--- a/ui/build/paths/config.go
+++ b/ui/build/paths/config.go
@@ -42,7 +42,7 @@
 }
 
 // This tool is specifically disallowed and calling it will result in an
-// "executable no found" error.
+// "executable not found" error.
 var Forbidden = PathConfig{
 	Symlink: false,
 	Log:     true,
@@ -122,6 +122,10 @@
 	"ld.bfd":     Forbidden,
 	"ld.gold":    Forbidden,
 	"pkg-config": Forbidden,
+	"python":     Forbidden,
+	"python2":    Forbidden,
+	"python2.7":  Forbidden,
+	"python3":    Forbidden,
 
 	// These are toybox tools that only work on Linux.
 	"pgrep": LinuxOnlyPrebuilt,