docs: fix minimum Node.js version to 14.18.0 (#48545)

fixes #42729

According to #42729, the minimum Node.js version of Next is `14.18.0`,
but some docs say `14.6.0`, and it's error-prone.
#42729 (comment)
pointed out it's a bug rather than wrong documentation.

But Node v14 is going to be EOF this month, so Next will update the
minimum version in the next major release.
https://github.com/nodejs/release#release-schedule

So I feel it's enough to only fix the documentation rather than fixing
the implementation to work with 14.6.0 as a temporary fix.


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---------

Co-authored-by: Steven <steven@ceriously.com>

docs/getting-started.md

@@ -14,7 +14,7 @@ If you have questions about anything related to Next.js, you're always welcome t
 
 #### System Requirements
 
-- [Node.js 14.6.0](https://nodejs.org/) or newer
+- [Node.js 14.18.0](https://nodejs.org/) or newer
 - MacOS, Windows (including WSL), and Linux are supported
 
 ## Automatic Setup

docs/upgrading.md

@@ -19,7 +19,7 @@ pnpm up next react react-dom eslint-config-next --latest
 ### v13 Summary
 
 - The [Supported Browsers](/docs/basic-features/supported-browsers-features.md) have been changed to drop Internet Explorer and target modern browsers.
-- The minimum Node.js version has been bumped from 12.22.0 to 14.6.0, since 12.x has reached end-of-life.
+- The minimum Node.js version has been bumped from 12.22.0 to 14.18.0, since 12.x has reached end-of-life.
 - The minimum React version has been bumped from 17.0.2 to 18.2.0.
 - The `swcMinify` configuration property was changed from `false` to `true`. See [Next.js Compiler](/docs/advanced-features/compiler.md) for more info.
 - The `next/image` import was renamed to `next/legacy/image`. The `next/future/image` import was renamed to `next/image`. A [codemod is available](/docs/advanced-features/codemods.md#next-image-to-legacy-image) to safely and automatically rename your imports.

package.json

@@ -243,7 +243,7 @@
     "@babel/traverse": "7.18.0"
   },
   "engines": {
-    "node": ">=14.6.0"
+    "node": ">=14.18.0"
   },
   "packageManager": "pnpm@7.24.3"
 }

packages/create-next-app/package.json

@@ -55,6 +55,6 @@
     "validate-npm-package-name": "3.0.0"
   },
   "engines": {
-    "node": ">=14.6.0"
+    "node": ">=14.18.0"
   }
 }

packages/next/package.json

@@ -315,6 +315,6 @@
     "caniuse-lite": "1.0.30001406"
   },
   "engines": {
-    "node": ">=14.6.0"
+    "node": ">=14.18.0"
   }
 }

packages/next/taskfile-swc.js

@@ -66,7 +66,7 @@ module.exports = function (task) {
         env: {
           targets: {
             // follow the version defined in packages/next/package.json#engine
-            node: '14.6.0',
+            node: '14.18.0',
           },
         },
         jsc: {