* Suppress ICU test if site or home URL is not an IDN

* Check if any domain labels start with `xn--` to determine if a domain is an IDN

* Return true if IDN domain found

* Update src/Admin/SiteHealth.php

Make `is_intl_extension_needed()` private

Co-authored-by: Weston Ruter <westonruter@google.com>

Co-authored-by: Weston Ruter <westonruter@google.com>

…ve-collection-schema-type

* 'develop' of github.com:ampproject/amp-wp:
  Raise PHPStan level to 4 in lib/common (#4686)
  Update dependency uuid to v8
  Update dependency webpack to v4.43.0
  Update dependency eslint-plugin-jest to v23.11.0
  Update dependency eslint-plugin-react to v7.20.0 (#4691)
  Update dependency postcss to v7.0.30 (#4649)
  Update dependency moment to v2.25.3 (#4639)
  Update dependency babel-jest to v26 (#4652)
  Update dependency uuid to v7.0.3 (#4490)
  Update dependency wp-coding-standards/wpcs to v2.3.0 (#4721)
  Suppress Site Health ICU test if site or home URL is not an IDN (#4698)
  Pin amp-experiment to v0.1 (#4690)
  Strip multiple BOM characters (#4683)
  Strip leading BOM and whitespace and trailing HTML comment before parsing validation response JSON (#4679)
  Disable share icons
  Use amp-embedly-card for Tiktok embeds
  Update dependency xwp/wp-dev-lib to v1.6.4
  Update dependency eslint to v7
  Update dependency terser-webpack-plugin to v2.3.6

…-phpstan-to-level-4

* 'develop' of github.com:ampproject/amp-wp:
  Update dependency @wordpress/scripts to v9.1.0
  Update dependency @wordpress/jest-puppeteer-axe to v1.8.0
  Update dependency @wordpress/url to v2.15.0
  Update dependency @wordpress/plugins to v2.16.0
  Raise PHPStan level to 4 in lib/common (#4686)
  Update dependency uuid to v8
  Update dependency webpack to v4.43.0
  Update dependency eslint-plugin-jest to v23.11.0
  Update dependency eslint-plugin-react to v7.20.0 (#4691)
  Update dependency postcss to v7.0.30 (#4649)
  Update dependency moment to v2.25.3 (#4639)
  Update dependency babel-jest to v26 (#4652)
  Update dependency uuid to v7.0.3 (#4490)
  Update dependency wp-coding-standards/wpcs to v2.3.0 (#4721)
  Update dependency @wordpress/e2e-test-utils to v4.7.0
  Suppress Site Health ICU test if site or home URL is not an IDN (#4698)
  Pin amp-experiment to v0.1 (#4690)
  Disable share icons
  Use amp-embedly-card for Tiktok embeds
  Update dependency terser-webpack-plugin to v2.3.6