Refactor and improve external URL checks

- Move external URL checks to its own module under `tests/`. This
  separates them from integration test, addressing long runs and
  frequent failures that led to ignoring test results.
- Move `check-desktop-runtime-errors` to `tests/checks` to keep all
  test-related checks into one directory.
- Replace `ts-node` with `vite` for running
  `check-desktop-runtime-errors` to maintain a consistent execution
  environment across checks.
- Implement a timeout for each fetch call.
- Be nice to external sources, wait 5 seconds before sending another
  request to an URL under same domain. This solves rate-limiting issues.
- Instead of running test on every push/pull request, run them only
  weekly.
- Do not run tests on each commit/PR but only scheduled (weekly) to
  minimize noise.
- Fix URLs are not captured correctly inside backticks or parenthesis.

tests/checks/desktop-runtime-errors/main.spec.ts

@@ -0,0 +1,40 @@
+import { test } from 'vitest';
+import { main } from './check-desktop-runtime-errors/main';
+import { COMMAND_LINE_FLAGS, CommandLineFlag } from './check-desktop-runtime-errors/cli-args';
+
+test('should have no desktop runtime errors', async () => {
+  // arrange
+  setCommandLineFlagsFromEnvironmentVariables();
+  let exitCode: number;
+  global.process.exit = (code?: number): never => {
+    exitCode = code;
+    return undefined as never;
+  };
+  // act
+  await main();
+  // assert
+  expect(exitCode).to.equal(0);
+}, {
+  timeout: 60 /* minutes */ * 10000,
+});
+
+/*
+  Map environment variables to CLI arguments for compatibility with Vitest.
+*/
+function setCommandLineFlagsFromEnvironmentVariables() {
+  const flagEnvironmentVariableKeyMappings: {
+    readonly [key in CommandLineFlag]: string;
+  } = {
+    [CommandLineFlag.ForceRebuild]: 'BUILD',
+    [CommandLineFlag.TakeScreenshot]: 'SCREENSHOT',
+  };
+  Object.entries(flagEnvironmentVariableKeyMappings)
+    .forEach(([flag, environmentVariableKey]) => {
+      if (process.env[environmentVariableKey] !== undefined) {
+        process.argv = [
+          ...process.argv,
+          COMMAND_LINE_FLAGS[flag],
+        ];
+      }
+    });
+}