Update chromedriver brew install instructions in contributing doc

[sumanthratna]

brew cask install was recently deprecated in favor of brew install --cask

[ijjk]

Stats from current PR

Default Server Mode (Increase detected ⚠️)

General

	vercel/next.js canary	sumanthratna/next.js docs/contributing-brew-chromedriver	Change
buildDuration	10.4s	10.4s	-62ms
nodeModulesSize	77.5 MB	77.5 MB	✓

Page Load Tests Overall increase ✓

	vercel/next.js canary	sumanthratna/next.js docs/contributing-brew-chromedriver	Change
/ failed reqs	0	0	✓
/ total time (seconds)	2.108	2.111	0
/ avg req/sec	1186.01	1184.24	⚠️ -1.77
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	1.506	1.471	-0.03
/error-in-render avg req/sec	1659.67	1699.44	+39.77

Client Bundles (main, webpack, commons)

	vercel/next.js canary	sumanthratna/next.js docs/contributing-brew-chromedriver	Change
677f882d2ed8..43e3.js gzip	13.1 kB	13.1 kB	✓
framework.HASH.js gzip	39 kB	39 kB	✓
main-712e20f..aa05.js gzip	6.63 kB	6.63 kB	✓
webpack-50be..df5b.js gzip	751 B	751 B	✓
Overall change	59.4 kB	59.4 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	sumanthratna/next.js docs/contributing-brew-chromedriver	Change
polyfills-af..9390.js gzip	31.3 kB	31.3 kB	✓
Overall change	31.3 kB	31.3 kB	✓

Client Pages

	vercel/next.js canary	sumanthratna/next.js docs/contributing-brew-chromedriver	Change
_app-2a09aa2..4a98.js gzip	1.28 kB	1.28 kB	✓
_error-8b758..aef6.js gzip	3.46 kB	3.46 kB	✓
hooks-c71ae4..70cd.js gzip	887 B	887 B	✓
index-bbee2f..528b.js gzip	227 B	227 B	✓
link-7faf09b..eba4.js gzip	1.64 kB	1.64 kB	✓
routerDirect..bf84.js gzip	303 B	303 B	✓
withRouter-a..5826.js gzip	302 B	302 B	✓
Overall change	8.09 kB	8.09 kB	✓

Client Build Manifests

	vercel/next.js canary	sumanthratna/next.js docs/contributing-brew-chromedriver	Change
_buildManifest.js gzip	321 B	321 B	✓
Overall change	321 B	321 B	✓

Rendered Page Sizes

	vercel/next.js canary	sumanthratna/next.js docs/contributing-brew-chromedriver	Change
index.html gzip	615 B	615 B	✓
link.html gzip	620 B	620 B	✓
withRouter.html gzip	608 B	608 B	✓
Overall change	1.84 kB	1.84 kB	✓

---

Serverless Mode

General

	vercel/next.js canary	sumanthratna/next.js docs/contributing-brew-chromedriver	Change
buildDuration	12.2s	12.1s	-112ms
nodeModulesSize	77.5 MB	77.5 MB	✓

Client Bundles (main, webpack, commons)

	vercel/next.js canary	sumanthratna/next.js docs/contributing-brew-chromedriver	Change
677f882d2ed8..43e3.js gzip	13.1 kB	13.1 kB	✓
framework.HASH.js gzip	39 kB	39 kB	✓
main-712e20f..aa05.js gzip	6.63 kB	6.63 kB	✓
webpack-50be..df5b.js gzip	751 B	751 B	✓
Overall change	59.4 kB	59.4 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	sumanthratna/next.js docs/contributing-brew-chromedriver	Change
polyfills-af..9390.js gzip	31.3 kB	31.3 kB	✓
Overall change	31.3 kB	31.3 kB	✓

Client Pages

	vercel/next.js canary	sumanthratna/next.js docs/contributing-brew-chromedriver	Change
_app-2a09aa2..4a98.js gzip	1.28 kB	1.28 kB	✓
_error-8b758..aef6.js gzip	3.46 kB	3.46 kB	✓
hooks-c71ae4..70cd.js gzip	887 B	887 B	✓
index-bbee2f..528b.js gzip	227 B	227 B	✓
link-7faf09b..eba4.js gzip	1.64 kB	1.64 kB	✓
routerDirect..bf84.js gzip	303 B	303 B	✓
withRouter-a..5826.js gzip	302 B	302 B	✓
Overall change	8.09 kB	8.09 kB	✓

Client Build Manifests

	vercel/next.js canary	sumanthratna/next.js docs/contributing-brew-chromedriver	Change
_buildManifest.js gzip	321 B	321 B	✓
Overall change	321 B	321 B	✓

Serverless bundles

	vercel/next.js canary	sumanthratna/next.js docs/contributing-brew-chromedriver	Change
_error.js	1 MB	1 MB	✓
404.html	2.67 kB	2.67 kB	✓
hooks.html	1.92 kB	1.92 kB	✓
index.js	1 MB	1 MB	✓
link.js	1.06 MB	1.06 MB	✓
routerDirect.js	1.05 MB	1.05 MB	✓
withRouter.js	1.05 MB	1.05 MB	✓
Overall change	5.18 MB	5.18 MB	✓

Commit: e417e63