Remove unsafeCache from benchmark + use cross-env for benchmark (#29425)

Fixes from @sokra's review of #29325



## Bug

- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Errors have helpful link attached, see `contributing.md`

## Feature

- [ ] Implements an existing feature request or RFC. Make sure the feature request has been accepted for implementation before opening a PR.
- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Documentation added
- [ ] Telemetry added. In case of a feature if it's used or not.
- [ ] Errors have helpful link attached, see `contributing.md`

## Documentation / Examples

- [ ] Make sure the linting passes

Author: timneutkens

bench/nested-deps/next.config.js

@@ -2,10 +2,6 @@ module.exports = {
   eslint: {
     ignoreDuringBuilds: true,
   },
-  webpack(config) {
-    config.module.unsafeCache = true
-    return config
-  },
   experimental: {
     swcLoader: true,
     swcMinify: true,

bench/nested-deps/package.json

@@ -1,11 +1,11 @@
 {
   "scripts": {
     "prepare": "rm -rf components && mkdir components && node ./fuzzponent.js -d 2 -s 206 -o components",
-    "dev": "NEXT_PRIVATE_LOCAL_WEBPACK5=1 ../../node_modules/.bin/next dev",
-    "build": "NEXT_PRIVATE_LOCAL_WEBPACK5=1 ../../node_modules/.bin/next build",
-    "start": "NEXT_PRIVATE_LOCAL_WEBPACK5=1 ../../node_modules/.bin/next start",
+    "dev": "cross-env NEXT_PRIVATE_LOCAL_WEBPACK5=1 ../../node_modules/.bin/next dev",
+    "build": "cross-env NEXT_PRIVATE_LOCAL_WEBPACK5=1 ../../node_modules/.bin/next build",
+    "start": "cross-env NEXT_PRIVATE_LOCAL_WEBPACK5=1 ../../node_modules/.bin/next start",
     "dev-nocache": "rm -rf .next && yarn dev",
-    "dev-cpuprofile-nocache": "rm -rf .next && NEXT_PRIVATE_LOCAL_WEBPACK5=1 node --cpu-prof ../../node_modules/.bin/next",
+    "dev-cpuprofile-nocache": "rm -rf .next && cross-env NEXT_PRIVATE_LOCAL_WEBPACK5=1 node --cpu-prof ../../node_modules/.bin/next",
     "build-nocache": "rm -rf .next && yarn build"
   }
 }