feat(settings): remove the platform mails switch

Broadcasts go to every active user, so the settings switch and its API
call are gone. Admin broadcast texts no longer mention an opt-out.

src/pages/SettingsPage.test.jsx

@@ -31,7 +31,6 @@ const authRoutes = (me) => ({
     'PUT /api/users/settings/appearance': noBody,
     'PUT /api/users/settings/profile-style': noBody,
     'PUT /api/users/settings/favorite-platform': noBody,
-    'PUT /api/users/settings/platform-mails': noBody,
     'GET /api/version': json(404, {}),
 });
 
@@ -257,29 +256,6 @@ describe('SettingsPage favorite platform', () => {
     });
 });
 
-describe('SettingsPage platform mails', () => {
-    beforeEach(() => localStorage.setItem('tbp_session', '1'));
-
-    afterEach(() => {
-        cleanup();
-        localStorage.clear();
-    });
-
-    it('is on by default and saves the opt-out', async () => {
-        toast.success.mockClear();
-        renderPage(profile());
-
-        const mails = await screen.findByRole('switch', {name: 'SETTINGS.PLATFORM_MAILS'});
-        expect(mails.getAttribute('aria-checked')).toBe('true');
-        fireEvent.click(mails);
-
-        await waitFor(() => expect(puts()).toEqual([{enabled: false}]));
-        expect(fetch.mock.calls.find(([, init]) => init?.method === 'PUT')[0]).toContain('/api/users/settings/platform-mails');
-        await waitFor(() => expect(toast.success).toHaveBeenCalledWith('SETTINGS.SAVED'));
-        expect(mails.getAttribute('aria-checked')).toBe('false');
-    });
-});
-
 describe('SettingsPage session', () => {
     beforeEach(() => localStorage.setItem('tbp_session', '1'));