[Lexical][CI] Add more ||ism in e2e tests to decrease overall run time

[Sahejkm]

WHAT

• Add ||ism in slow test files by changing test.describe to test.describe.parallel
• Add ||ism in workers - in CI we were using just 1 worker while in local dev machines we use 4 workers, change to 4 workers in CI as well to make the tests run faster

https://playwright.dev/docs/test-parallel

WHY

• Lower the running time for github workflows related to e2e tests and hence lower the spend

Test Plan

Before: https://github.com/facebook/lexical/actions/runs/9342978263/usage?pr=6198
~6h

After: https://github.com/facebook/lexical/actions/runs/9344275667/usage?pr=6237
~3h 45min

[vercel]

The latest updates on your projects. Learn more about Vercel for Git ↗︎

Name	Status	Preview	Comments	Updated (UTC)
lexical	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Jun 3, 2024 4:28am
lexical-playground	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Jun 3, 2024 4:28am

[github-actions]

size-limit report 📦

Path	Size
lexical - cjs	28.33 KB (0%)
lexical - esm	28.14 KB (0%)
@lexical/rich-text - cjs	36.72 KB (-0.11% 🔽)
@lexical/rich-text - esm	28.1 KB (0%)
@lexical/plain-text - cjs	35.37 KB (0%)
@lexical/plain-text - esm	25.33 KB (0%)
@lexical/react - cjs	38.52 KB (0%)
@lexical/react - esm	29.12 KB (0%)

[Sahejkm]

cancelled pull_request_review workflow manually causing re-trigger of extended tests run, the label 'extended-tests' was already there, it shouldn't have rerun the tests, unless the label was manually removed. will investigate separately