iCloud.com on desktop gives "Your browser is not supported" error message

Description

Visiting iCloud.com in any Brave build at this time lands you on Your browser is not supported error page. Shields up/down do not appear to make a difference, nether does a fresh profile or clearing cache/site data. No errors shown in dev tools console.

Steps to Reproduce

1. Visit https://icloud.com

Reproduces how often:

Always

Brave version (brave://version info)

Version 1.29.81 Chromium: 93.0.4577.82 (Official Build) (x86_64)

Version/Channel Information:

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

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields? No
• Does the issue resolve itself when disabling Brave Rewards? No
• Is the issue reproducible on the latest version of Chrome? No

Miscellaneous Information:

User reports: https://community.brave.com/t/just-got-your-browser-is-not-supported-from-icloud-com/284365/6 https://old.reddit.com/r/brave_browser/comments/ps03fa/wwwicloudcom_no_longer_works_with_brave/

[ryanbr]

Re-open to confirm the fix is working with everyone.

[antonok-edm]

@valynor we’re getting the solution from https://github.com/brave/brave-core/pull/10192 into the next hotfix release, which should be coming out later today.