Fix accessing headers in progressively enhanced form actions

[unstubbable]

When scoping the requestStore to dynamic renders in #72312, we missed the case when a server action is invoked before hydration is complete.

This leads to an error when a server action tries to read headers, cookies, or anything else that requires the presence of the requestStore.

This fixes that for both the Node.js and Edge runtimes. It also appears that progressively enhanced form actions did not work at all before in the Edge runtime due to a missing await of decodeFormState.

fixes #73992
closes NAR-55

[ijjk]

Stats from current PR

Default Build (Increase detected ⚠️)

General Overall increase ⚠️

	vercel/next.js canary	vercel/next.js hl/headers-in-pe-server-action	Change
buildDuration	19.2s	16s	N/A
buildDurationCached	15.1s	12.7s	N/A
nodeModulesSize	416 MB	416 MB	⚠️ +7.55 kB
nextStartRea..uration (ms)	476ms	471ms	N/A

Client Bundles (main, webpack)

	vercel/next.js canary	vercel/next.js hl/headers-in-pe-server-action	Change
1187-HASH.js gzip	52.4 kB	52.4 kB	N/A
8276.HASH.js gzip	169 B	168 B	N/A
8377-HASH.js gzip	5.36 kB	5.36 kB	N/A
bccd1874-HASH.js gzip	52.8 kB	52.8 kB	N/A
framework-HASH.js gzip	57.5 kB	57.5 kB	N/A
main-app-HASH.js gzip	232 B	235 B	N/A
main-HASH.js gzip	34.1 kB	34.1 kB	N/A
webpack-HASH.js gzip	1.71 kB	1.71 kB	N/A
Overall change	0 B	0 B	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	vercel/next.js hl/headers-in-pe-server-action	Change
polyfills-HASH.js gzip	39.4 kB	39.4 kB	✓
Overall change	39.4 kB	39.4 kB	✓

Client Pages

	vercel/next.js canary	vercel/next.js hl/headers-in-pe-server-action	Change
_app-HASH.js gzip	193 B	193 B	✓
_error-HASH.js gzip	193 B	193 B	✓
amp-HASH.js gzip	512 B	510 B	N/A
css-HASH.js gzip	343 B	342 B	N/A
dynamic-HASH.js gzip	1.84 kB	1.84 kB	✓
edge-ssr-HASH.js gzip	265 B	265 B	✓
head-HASH.js gzip	363 B	362 B	N/A
hooks-HASH.js gzip	393 B	392 B	N/A
image-HASH.js gzip	4.49 kB	4.49 kB	N/A
index-HASH.js gzip	268 B	268 B	✓
link-HASH.js gzip	2.35 kB	2.34 kB	N/A
routerDirect..HASH.js gzip	328 B	328 B	✓
script-HASH.js gzip	397 B	397 B	✓
withRouter-HASH.js gzip	323 B	326 B	N/A
1afbb74e6ecf..834.css gzip	106 B	106 B	✓
Overall change	3.59 kB	3.59 kB	✓

Client Build Manifests

	vercel/next.js canary	vercel/next.js hl/headers-in-pe-server-action	Change
_buildManifest.js gzip	749 B	746 B	N/A
Overall change	0 B	0 B	✓

Rendered Page Sizes

	vercel/next.js canary	vercel/next.js hl/headers-in-pe-server-action	Change
index.html gzip	524 B	524 B	✓
link.html gzip	538 B	538 B	✓
withRouter.html gzip	520 B	521 B	N/A
Overall change	1.06 kB	1.06 kB	✓

Edge SSR bundle Size

	vercel/next.js canary	vercel/next.js hl/headers-in-pe-server-action	Change
edge-ssr.js gzip	129 kB	129 kB	N/A
page.js gzip	206 kB	206 kB	N/A
Overall change	0 B	0 B	✓

Middleware size

	vercel/next.js canary	vercel/next.js hl/headers-in-pe-server-action	Change
middleware-b..fest.js gzip	670 B	665 B	N/A
middleware-r..fest.js gzip	155 B	156 B	N/A
middleware.js gzip	31.3 kB	31.3 kB	N/A
edge-runtime..pack.js gzip	844 B	844 B	✓
Overall change	844 B	844 B	✓

Next Runtimes

	vercel/next.js canary	vercel/next.js hl/headers-in-pe-server-action	Change
274-experime...dev.js gzip	322 B	322 B	✓
274.runtime.dev.js gzip	314 B	314 B	✓
app-page-exp...dev.js gzip	359 kB	359 kB	N/A
app-page-exp..prod.js gzip	129 kB	129 kB	N/A
app-page-tur..prod.js gzip	142 kB	142 kB	N/A
app-page-tur..prod.js gzip	137 kB	137 kB	N/A
app-page.run...dev.js gzip	347 kB	347 kB	N/A
app-page.run..prod.js gzip	125 kB	125 kB	N/A
app-route-ex...dev.js gzip	37.5 kB	37.5 kB	✓
app-route-ex..prod.js gzip	25.5 kB	25.5 kB	✓
app-route-tu..prod.js gzip	25.5 kB	25.5 kB	✓
app-route-tu..prod.js gzip	25.4 kB	25.4 kB	✓
app-route.ru...dev.js gzip	39.2 kB	39.2 kB	✓
app-route.ru..prod.js gzip	25.4 kB	25.4 kB	✓
pages-api-tu..prod.js gzip	9.69 kB	9.69 kB	✓
pages-api.ru...dev.js gzip	11.6 kB	11.6 kB	✓
pages-api.ru..prod.js gzip	9.68 kB	9.68 kB	✓
pages-turbo...prod.js gzip	21.7 kB	21.7 kB	✓
pages.runtim...dev.js gzip	27.5 kB	27.5 kB	✓
pages.runtim..prod.js gzip	21.7 kB	21.7 kB	✓
server.runti..prod.js gzip	916 kB	916 kB	✓
Overall change	1.2 MB	1.2 MB	✓

build cache Overall increase ⚠️

	vercel/next.js canary	vercel/next.js hl/headers-in-pe-server-action	Change
0.pack gzip	2.08 MB	2.08 MB	⚠️ +3.53 kB
index.pack gzip	74.2 kB	74.5 kB	⚠️ +374 B
Overall change	2.15 MB	2.16 MB	⚠️ +3.9 kB

Diff details

Diff for main-HASH.js

Diff too large to display

Diff for app-page-exp..ntime.dev.js

Diff too large to display

Diff for app-page-exp..time.prod.js

Diff too large to display

Diff for app-page-tur..time.prod.js

Diff too large to display

Diff for app-page-tur..time.prod.js

Diff too large to display

Diff for app-page.runtime.dev.js

Diff too large to display

Diff for app-page.runtime.prod.js

Diff too large to display

Commit: 322282f