Bug 1675326 - part2 : move webvtt related xpcshell test to `dom/media/webvtt/test/xpcshell` r=bryce

Depends on D96103

Differential Revision: https://phabricator.services.mozilla.com/D96104

dom/media/webvtt/moz.build

@@ -41,6 +41,6 @@ EXTRA_JS_MODULES += [
     "vtt.jsm",
 ]
 
-XPCSHELL_TESTS_MANIFESTS += ["tests/xpcshell.ini"]
+XPCSHELL_TESTS_MANIFESTS += ["test/xpcshell/xpcshell.ini"]
 
 FINAL_LIBRARY = "xul"

dom/media/webvtt/tests/.eslintrc.js

@@ -1,5 +0,0 @@
-"use strict";
-
-module.exports = {
-  extends: ["plugin:mozilla/xpcshell-test"],
-};