puppeteer_tests: Remove login test.

This commit deletes the `01-login.ts` test because it was
redundant, We are already checking for log-in in all the
other tests.

frontend_tests/puppeteer_tests/01-login.ts

@@ -1,10 +0,0 @@
-import type {Page} from "puppeteer";
-
-import {test_credentials} from "../../var/puppeteer/test_credentials";
-import common from "../puppeteer_lib/common";
-
-async function login_tests(page: Page): Promise<void> {
-    await common.log_in(page, test_credentials.default_user);
-}
-
-common.run_test(login_tests);