Prerender: Remove unused imports of deferred-promise-utils.js

This CL removes unused imports of deferred-promise-utils.js from
window-move.html and window-resize.html.

Bug: 1253158
Change-Id: I835545280025ed1a6e3c20ccdd626eb4dec5863f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3231136
Reviewed-by: Lingqi Chi <lingqi@chromium.org>
Commit-Queue: Hiroki Nakagawa <nhiroki@chromium.org>
Cr-Commit-Position: refs/heads/main@{#932958}
diff --git a/speculation-rules/prerender/resources/window-move.html b/speculation-rules/prerender/resources/window-move.html
index bccaec5..02013a6 100644
--- a/speculation-rules/prerender/resources/window-move.html
+++ b/speculation-rules/prerender/resources/window-move.html
@@ -2,7 +2,6 @@
 <script src="/resources/testharness.js"></script>
 <script src="/resources/testharnessreport.js"></script>
 <script src="utils.js"></script>
-<script src="deferred-promise-utils.js"></script>
 <script>
 
 const params = new URLSearchParams(location.search);
diff --git a/speculation-rules/prerender/resources/window-resize.html b/speculation-rules/prerender/resources/window-resize.html
index 7edb1f7..d8ae493 100644
--- a/speculation-rules/prerender/resources/window-resize.html
+++ b/speculation-rules/prerender/resources/window-resize.html
@@ -2,7 +2,6 @@
 <script src="/resources/testharness.js"></script>
 <script src="/resources/testharnessreport.js"></script>
 <script src="utils.js"></script>
-<script src="deferred-promise-utils.js"></script>
 <script>
 
 function tryRun(func) {