Dashboard: Remove playwright tests, checkly (#8269)

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## PR-Codex overview
This PR primarily focuses on the removal of various test files and configurations related to the `dashboard` application, alongside updates to the `package.json` and `pnpm-lock.yaml` files to reflect changes in dependencies.

### Detailed summary
- Deleted multiple test files in `apps/dashboard/tests`.
- Removed configuration files: `setup.ts`, `README.md`, `checkly.config.ts`, and `playwright.config.ts`.
- Updated `package.json` to remove dependencies related to `checkly` and `playwright`.
- Adjusted `pnpm-lock.yaml` to reflect the removal of certain packages and their dependencies.

> The following files were skipped due to too many changes: `pnpm-lock.yaml`

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<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit

* **Chores**
  * Removed end-to-end testing infrastructure, configuration, helper utilities, test runner scripts, and related dev dependencies from the dashboard app.
* **Documentation**
  * Deleted the dashboard E2E testing README and related test documentation.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Author: MananTank

apps/dashboard/checkly.config.ts

@@ -82,7 +82,6 @@
     "@chromatic-com/storybook": "4.0.1",
     "@next/bundle-analyzer": "15.3.5",
     "@next/eslint-plugin-next": "15.3.5",
-    "@playwright/test": "1.53.2",
     "@storybook/addon-docs": "9.0.15",
     "@storybook/addon-links": "9.0.15",
     "@storybook/addon-onboarding": "9.0.15",
@@ -99,7 +98,6 @@
     "@typescript-eslint/eslint-plugin": "7.14.1",
     "@typescript-eslint/parser": "7.14.1",
     "autoprefixer": "^10.4.21",
-    "checkly": "6.0.1",
     "eslint": "8.57.0",
     "eslint-config-biome": "1.9.4",
     "eslint-plugin-react-compiler": "19.1.0-rc.2",
@@ -122,13 +120,11 @@
     "format": "biome format ./src --write",
     "knip": "knip",
     "lint": "biome check ./src && knip && eslint ./src",
-    "playwright": "playwright test",
     "postbuild": "next-sitemap",
     "preinstall": "npx only-allow pnpm",
     "start": "next start",
     "storybook": "storybook dev -p 6006",
-    "typecheck": "tsc --noEmit",
-    "update-checkly": "npx checkly deploy"
+    "typecheck": "tsc --noEmit"
   },
   "version": "3.0.0"
 }