Bug 1509468 [wpt PR 14202] - [Azure Pipelines] Don't pin Safari Technology Preview version, a=testonly

Automatic update from web-platform-tests
[Azure Pipelines] Don't pin Safari Technology Preview version (#14202)

Fixes https://github.com/web-platform-tests/wpt/issues/13800.
--

wpt-commits: 4b6b5524b1203233d78d025312b6e918809286f3
wpt-pr: 14202

testing/web-platform/tests/tools/ci/azure/install_safari.yml

@@ -1,8 +1,6 @@
 steps:
 - script: |
-    # Pin to STP 67, as SafariDriver isn't working in 68:
-    # https://github.com/web-platform-tests/wpt/issues/13800
-    HOMEBREW_NO_AUTO_UPDATE=1 brew cask install https://raw.githubusercontent.com/Homebrew/homebrew-cask-versions/23fae0a88868911913c2ee7d527c89164b6d5720/Casks/safari-technology-preview.rb
+    HOMEBREW_NO_AUTO_UPDATE=1 brew cask install Homebrew/homebrew-cask-versions/safari-technology-preview
     # https://web-platform-tests.org/running-tests/safari.html
     sudo "/Applications/Safari Technology Preview.app/Contents/MacOS/safaridriver" --enable
     defaults write com.apple.Safari WebKitJavaScriptCanOpenWindowsAutomatically 1