test: use 4 workers, disable timezone test (#5044)

# What this PR does
Toggle off timezone test temporarily
Use 4 workers always

## Which issue(s) this PR closes

Related to [issue link here]

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## Checklist

- [ ] Unit, integration, and e2e (if applicable) tests updated
- [x] Documentation added (or `pr:no public docs` PR label added if not
required)
- [x] Added the relevant release notes label (see labels prefixed w/
`release:`). These labels dictate how your PR will
    show up in the autogenerated release notes.

grafana-plugin/e2e-tests/schedules/timezones.test.ts

@@ -14,7 +14,8 @@ dayjs.extend(isoWeek);
 
 test.use({ timezoneId: MOSCOW_TIMEZONE }); // GMT+3 the whole year
 
-test('dates in schedule are correct according to selected current timezone', async ({ adminRolePage }) => {
+// The test is skipped because using Clock API breaks several other tests that run in parallel
+test.skip('dates in schedule are correct according to selected current timezone', async ({ adminRolePage }) => {
   const { page, userName } = adminRolePage;
 
   /**

grafana-plugin/playwright.config.ts

@@ -53,9 +53,7 @@ export default defineConfig({
    * to flaky tests.. let's allow 1 retry per test
    */
   retries: 1,
-  workers: '25%', // 25% of logical CPU cores, e.g. for 16 CPU cores it will use 4 workers
-  /* Reporter to use. See https://playwright.dev/docs/test-reporters */
-  // reporter: 'html',
+  workers: 4,
   /* Shared settings for all the projects below. See https://playwright.dev/docs/api/class-testoptions. */
   use: {
     /* Maximum time each action such as `click()` can take. Defaults to 0 (no limit). */