Prevent SpeechSynthesis interface readout for increased privacy

[pilsnerbeer]

Description

The SpeechSynthesis access can be used to determine user's location when using VPN. Currently it is the only thing that (in my case) exposes this as defalut language/timezone can be changed but not installed speech (in Windows). Default speech package can not be uninstalled by conventional means as far as I've tried (only new packages can be added). I dont think I ever took advantage of speechSynthesis (?), so would it be beneficial turning it off by default in Brave?

Steps to Reproduce

1. visit https://browserleaks.com/javascript#speech
2. see currently installed speech voice

Actual result:

Expected result:

Reproduces how often:

always

Brave	1.34.81 Chromium: 97.0.4692.99 (Official Build) (64-bit)
Revision	d740da257583289dbebd2eb37e8668928fac5ead-refs/branch-heads/4692@{#1461}
OS	Windows 10 Version 21H1 (Build 19043.1466)
JavaScript	V8 9.7.106.19
User Agent	Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/97.0.4692.99 Safari/537.36

Version/Channel Information:

• Can you reproduce this issue with the current release?
• Can you reproduce this issue with the beta channel?
• Can you reproduce this issue with the nightly channel?