Build Tools: Don't run the build task twice in grunt prerelease (it already runs via the precommit:js task).

Props netweb.
Fixes #36489.

git-svn-id: https://develop.svn.wordpress.org/trunk@37206 602fd350-edb4-49c9-b593-d223f7449a82

Gruntfile.js

@@ -769,8 +769,7 @@ module.exports = function(grunt) {
 		'precommit:php',
 		'precommit:js',
 		'precommit:css',
-		'precommit:base',
-		'build'
+		'precommit:base'
 	] );
 
 	// Testing tasks.