Discovered as part of #88391

Looks like some of out built-in extensions are still using rootPath:

• Php @roblourens

  vscode/extensions/php-language-features/src/features/validationProvider.ts

  Line 250 in ca22de4

  let options = vscode.workspace.rootPath ? { cwd: vscode.workspace.rootPath } : undefined;

• Emmet @octref

  vscode/extensions/emmet/src/util.ts

  Line 35 in 99d5ff9

  _emmetHelper.updateExtensionsPath(extensionsPath, vscode.workspace.rootPath).then(null, (err: string) => vscode.window.showErrorMessage(err));

• json @aeschli

  vscode/extensions/json-language-features/client/src/jsonMain.ts

  Line 415 in ce31ace

  collectSchemaSettings(globalSettings, workspace.rootPath);