Don't use yarn if a package-lock.json file is found

[thibautsabot]

Fixes #31755

[ijjk]

Stats from current PR

Default Build (Decrease detected ✓)

General Overall increase ⚠️

	vercel/next.js canary	thibautsabot/next.js dont-use-yarn-if-package-lock	Change
buildDuration	15.5s	15.3s	-264ms
buildDurationCached	6.1s	5.9s	-119ms
nodeModulesSize	359 MB	359 MB	⚠️ +891 B

Page Load Tests Overall decrease ⚠️

	vercel/next.js canary	thibautsabot/next.js dont-use-yarn-if-package-lock	Change
/ failed reqs	0	0	✓
/ total time (seconds)	3.224	3.411	⚠️ +0.19
/ avg req/sec	775.47	732.95	⚠️ -42.52
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	1.347	1.392	⚠️ +0.04
/error-in-render avg req/sec	1856.45	1795.53	⚠️ -60.92

Client Bundles (main, webpack, commons)

	vercel/next.js canary	thibautsabot/next.js dont-use-yarn-if-package-lock	Change
450.HASH.js gzip	179 B	179 B	✓
framework-HASH.js gzip	42.2 kB	42.2 kB	✓
main-HASH.js gzip	27.4 kB	27.4 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	thibautsabot/next.js dont-use-yarn-if-package-lock	Change
polyfills-HASH.js gzip	31 kB	31 kB	✓
Overall change	31 kB	31 kB	✓

Client Pages

	vercel/next.js canary	thibautsabot/next.js dont-use-yarn-if-package-lock	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	2.37 kB	2.37 kB	✓
head-HASH.js gzip	350 B	350 B	✓
hooks-HASH.js gzip	919 B	919 B	✓
image-HASH.js gzip	4.94 kB	4.94 kB	✓
index-HASH.js gzip	263 B	263 B	✓
link-HASH.js gzip	2.19 kB	2.19 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	14.3 kB	14.3 kB	✓

Client Build Manifests

	vercel/next.js canary	thibautsabot/next.js dont-use-yarn-if-package-lock	Change
_buildManifest.js gzip	459 B	459 B	✓
Overall change	459 B	459 B	✓

Rendered Page Sizes

	vercel/next.js canary	thibautsabot/next.js dont-use-yarn-if-package-lock	Change
index.html gzip	532 B	532 B	✓
link.html gzip	546 B	546 B	✓
withRouter.html gzip	526 B	526 B	✓
Overall change	1.6 kB	1.6 kB	✓

---

Default Build with SWC (Decrease detected ✓)

General Overall increase ⚠️

	vercel/next.js canary	thibautsabot/next.js dont-use-yarn-if-package-lock	Change
buildDuration	19.1s	19.8s	⚠️ +696ms
buildDurationCached	6.3s	7s	⚠️ +675ms
nodeModulesSize	359 MB	359 MB	⚠️ +891 B

Page Load Tests Overall decrease ⚠️

	vercel/next.js canary	thibautsabot/next.js dont-use-yarn-if-package-lock	Change
/ failed reqs	0	0	✓
/ total time (seconds)	3.237	3.514	⚠️ +0.28
/ avg req/sec	772.31	711.53	⚠️ -60.78
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	1.368	1.568	⚠️ +0.2
/error-in-render avg req/sec	1827.36	1594.61	⚠️ -232.75

Client Bundles (main, webpack, commons)

	vercel/next.js canary	thibautsabot/next.js dont-use-yarn-if-package-lock	Change
450.HASH.js gzip	179 B	179 B	✓
framework-HASH.js gzip	42.3 kB	42.3 kB	✓
main-HASH.js gzip	27.4 kB	27.4 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	thibautsabot/next.js dont-use-yarn-if-package-lock	Change
polyfills-HASH.js gzip	31 kB	31 kB	✓
Overall change	31 kB	31 kB	✓

Client Pages

	vercel/next.js canary	thibautsabot/next.js dont-use-yarn-if-package-lock	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	2.36 kB	2.36 kB	✓
head-HASH.js gzip	342 B	342 B	✓
hooks-HASH.js gzip	911 B	911 B	✓
image-HASH.js gzip	4.97 kB	4.97 kB	✓
index-HASH.js gzip	256 B	256 B	✓
link-HASH.js gzip	2.21 kB	2.21 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	14.3 kB	14.3 kB	✓

Client Build Manifests

	vercel/next.js canary	thibautsabot/next.js dont-use-yarn-if-package-lock	Change
_buildManifest.js gzip	459 B	459 B	✓
Overall change	459 B	459 B	✓

Rendered Page Sizes

	vercel/next.js canary	thibautsabot/next.js dont-use-yarn-if-package-lock	Change
index.html gzip	533 B	533 B	✓
link.html gzip	546 B	546 B	✓
withRouter.html gzip	528 B	528 B	✓
Overall change	1.61 kB	1.61 kB	✓

Commit: ed3265c