Deprecate concurrentFeatures with runtime

[shuding]

As noted in #31317, this PR removes experimental.concurrentFeatures with the new experimental.runtime flag. The new runtime currently controls the global Fizz runtime which can be set to:

• undefined: default value, disables Fizz
• 'edge': the concurrentFeatures behavior, enables Fizz with the edge runtime for all pages
• 'nodejs': enables Fizz with the node runtime for all pages

Todos

• Update corresponding docs
• Add basic tests for the new 'nodejs' runtime

[huozhi]

Looks great 🚀

[ijjk]

Failing test suites

Commit: c6a8413

yarn testheadless test/integration/middleware/core/test/index.test.js

• Middleware base tests > dev mode > /fr should rewrite to Vercel

Expand output

● Middleware base tests › dev mode › /fr should rewrite to Vercel

expect(received).toBe(expected) // Object.is equality

Expected: "Develop. Preview. Ship. For the best frontend teams – Vercel"
Received: ""

  332 |     // const browser = await webdriver(context.appPort, '/rewrite-me-to-vercel')
  333 |     // TODO: running this to chech the window.location.pathname hangs for some reason;
> 334 |     expect($('head > title').text()).toBe(
      |                                      ^
  335 |       'Develop. Preview. Ship. For the best frontend teams – Vercel'
  336 |     )
  337 |   })

  at Object.<anonymous> (integration/middleware/core/test/index.test.js:334:38)

Read more about building and testing Next.js in contributing.md.

[ijjk]

Stats from current PR

Default Build (Increase detected ⚠️)

General Overall increase ⚠️

	vercel/next.js canary	shuding/next.js shu/ee56	Change
buildDuration	14.9s	14.9s	⚠️ +10ms
buildDurationCached	5.9s	6.2s	⚠️ +302ms
nodeModulesSize	359 MB	359 MB	⚠️ +3.77 kB

Page Load Tests Overall increase ✓

	vercel/next.js canary	shuding/next.js shu/ee56	Change
/ failed reqs	0	0	✓
/ total time (seconds)	2.931	2.918	-0.01
/ avg req/sec	853.01	856.76	+3.75
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	1.133	1.124	-0.01
/error-in-render avg req/sec	2206.9	2223.81	+16.91

Client Bundles (main, webpack, commons)

	vercel/next.js canary	shuding/next.js shu/ee56	Change
450.HASH.js gzip	179 B	179 B	✓
framework-HASH.js gzip	42 kB	42 kB	✓
main-HASH.js gzip	27.5 kB	27.5 kB	✓
webpack-HASH.js gzip	1.44 kB	1.44 kB	✓
Overall change	71.2 kB	71.2 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	shuding/next.js shu/ee56	Change
polyfills-HASH.js gzip	31 kB	31 kB	✓
Overall change	31 kB	31 kB	✓

Client Pages

	vercel/next.js canary	shuding/next.js shu/ee56	Change
_app-HASH.js gzip	1.36 kB	1.36 kB	✓
_error-HASH.js gzip	194 B	194 B	✓
amp-HASH.js gzip	312 B	312 B	✓
css-HASH.js gzip	326 B	326 B	✓
dynamic-HASH.js gzip	2.57 kB	2.57 kB	✓
head-HASH.js gzip	350 B	350 B	✓
hooks-HASH.js gzip	919 B	919 B	✓
image-HASH.js gzip	5.01 kB	5.01 kB	✓
index-HASH.js gzip	263 B	263 B	✓
link-HASH.js gzip	2.26 kB	2.26 kB	✓
routerDirect..HASH.js gzip	321 B	321 B	✓
script-HASH.js gzip	383 B	383 B	✓
withRouter-HASH.js gzip	318 B	318 B	✓
85e02e95b279..7e3.css gzip	107 B	107 B	✓
Overall change	14.7 kB	14.7 kB	✓

Client Build Manifests

	vercel/next.js canary	shuding/next.js shu/ee56	Change
_buildManifest.js gzip	458 B	458 B	✓
Overall change	458 B	458 B	✓

Rendered Page Sizes

	vercel/next.js canary	shuding/next.js shu/ee56	Change
index.html gzip	531 B	531 B	✓
link.html gzip	544 B	544 B	✓
withRouter.html gzip	525 B	525 B	✓
Overall change	1.6 kB	1.6 kB	✓

---

Default Build with SWC (Decrease detected ✓)

General Overall increase ⚠️

	vercel/next.js canary	shuding/next.js shu/ee56	Change
buildDuration	18.3s	18.5s	⚠️ +222ms
buildDurationCached	5.9s	5.8s	-91ms
nodeModulesSize	359 MB	359 MB	⚠️ +3.77 kB

Page Load Tests Overall decrease ⚠️

	vercel/next.js canary	shuding/next.js shu/ee56	Change
/ failed reqs	0	0	✓
/ total time (seconds)	2.936	2.946	⚠️ +0.01
/ avg req/sec	851.64	848.58	⚠️ -3.06
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	1.136	1.135	0
/error-in-render avg req/sec	2201.22	2203.12	+1.9

Client Bundles (main, webpack, commons)

	vercel/next.js canary	shuding/next.js shu/ee56	Change
450.HASH.js gzip	179 B	179 B	✓
framework-HASH.js gzip	42.1 kB	42.1 kB	✓
main-HASH.js gzip	27.5 kB	27.5 kB	✓
webpack-HASH.js gzip	1.44 kB	1.44 kB	✓
Overall change	71.3 kB	71.3 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	shuding/next.js shu/ee56	Change
polyfills-HASH.js gzip	31 kB	31 kB	✓
Overall change	31 kB	31 kB	✓

Client Pages

	vercel/next.js canary	shuding/next.js shu/ee56	Change
_app-HASH.js gzip	1.35 kB	1.35 kB	✓
_error-HASH.js gzip	180 B	180 B	✓
amp-HASH.js gzip	305 B	305 B	✓
css-HASH.js gzip	321 B	321 B	✓
dynamic-HASH.js gzip	2.56 kB	2.56 kB	✓
head-HASH.js gzip	342 B	342 B	✓
hooks-HASH.js gzip	911 B	911 B	✓
image-HASH.js gzip	5.05 kB	5.05 kB	✓
index-HASH.js gzip	256 B	256 B	✓
link-HASH.js gzip	2.28 kB	2.28 kB	✓
routerDirect..HASH.js gzip	314 B	314 B	✓
script-HASH.js gzip	375 B	375 B	✓
withRouter-HASH.js gzip	309 B	309 B	✓
85e02e95b279..7e3.css gzip	107 B	107 B	✓
Overall change	14.7 kB	14.7 kB	✓

Client Build Manifests

	vercel/next.js canary	shuding/next.js shu/ee56	Change
_buildManifest.js gzip	460 B	460 B	✓
Overall change	460 B	460 B	✓

Rendered Page Sizes

	vercel/next.js canary	shuding/next.js shu/ee56	Change
index.html gzip	533 B	533 B	✓
link.html gzip	547 B	547 B	✓
withRouter.html gzip	527 B	527 B	✓
Overall change	1.61 kB	1.61 kB	✓

Commit: 2b096e6