Fix Linux sanity UI test for Restricted-Mode-first workspace trust flow

[Copilot]

Description

Since untrusted workspaces now open directly in Restricted Mode (workspace.trust.startupPrompt defaults to 'never'), the modal workspace-trust dialog is no longer shown on startup. The sanity UI harness still waited for the modal's "Yes, I trust the authors" button, so desktop-linux-x64 and server-web-linux-x64 timed out after 180s.

Updated test/sanity/src/uiTest.ts to grant trust via the new affordance instead of the removed modal:

• Replaced dismissWorkspaceTrustDialog (waited for the modal button) with grantWorkspaceTrust.
• grantWorkspaceTrust runs the Workspaces: Manage Workspace Trust command and clicks the Trust button in the workspace trust editor.

private async grantWorkspaceTrust(page: Page) {
	this.context.log('Granting workspace trust');
	await this.runCommand(page, 'Workspaces: Manage Workspace Trust');
	const trustButton = page.locator('.workspace-trust-buttons .monaco-button', { hasText: /^Trust$/ }).first();
	await trustButton.click();
	await page.waitForTimeout(500);
}

[rwoll]

@copilot you will then need to click the "Close Modal Editor" to save it.

[dmitrivMS]

Clicking Trust does not close the dialog?

[rwoll]

No, the Manage Trust full UI is different than the Modal.

@copilot - you will need to click "Close Modal Editor" (that's the hover text) after clicking the Trust button.