Build Tools: Replace deprecated browserslist --update-db command.

Replaces the deprecated `--update-db` command in the `browserslist:update` Grunt task with `update-browserslist-db@latest`.

Props ekla, sergeybiryukov, masteradhoc.

Fixes #64900.


git-svn-id: https://develop.svn.wordpress.org/trunk@62570 602fd350-edb4-49c9-b593-d223f7449a82

Author: cbravobernal

Gruntfile.js

@@ -2370,7 +2370,7 @@ module.exports = function(grunt) {
 
 	grunt.registerTask( 'browserslist:update', 'Update the local database of browser supports', function() {
 		grunt.log.writeln( `Updating browsers list` );
-		spawn( 'npx', [ 'browserslist@latest', '--update-db' ], {
+		spawn( 'npx', [ 'update-browserslist-db@latest' ], {
 			cwd: __dirname,
 			stdio: 'inherit',
 		} );