deps: V8: cherry-pick a7dffcd767be

Original commit message:

    [postmortem] Load files using utf-8 to support Python 3

    Change-Id: I174d38cc33210c07d1a7596627e1b2d21bb06313
    Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1895560


Reviewed-by: Mathias Bynens <mathias@chromium.org>
    Commit-Queue: Michaël Zasso <mic.besace@gmail.com>
    Cr-Commit-Position: refs/heads/master@{#64717}

Refs: https://github.com/v8/v8/commit/a7dffcd767be6e6122dd3911c8388b5ff76ac590

PR-URL: https://github.com/nodejs/node/pull/30218


Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: David Carlier <devnexen@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Chengzhong Wu <legendecas@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>