Increase shards for test262 on V8 Linux64 ASAN

Change-Id: I9499aacb4ddf4bc2afc3c72666910b4ad756cfc1
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3400969
Auto-Submit: Almothana Athamneh <almuthanna@chromium.org>
Commit-Queue: Almothana Athamneh <almuthanna@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/main@{#78682}

infra/testing/builders.pyl

@@ -1383,7 +1383,7 @@
       'os': 'Ubuntu-18.04',
     },
     'tests': [
-      {'name': 'test262', 'shards': 5},
+      {'name': 'test262', 'shards': 7},
       {'name': 'v8testing', 'shards': 2},
       {'name': 'v8testing', 'variant': 'extra', 'shards': 2},
       {'name': 'v8testing', 'variant': 'slow_path', 'shards': 1},