Separate build script from install script #4458

The --build-from-source flag is now deprecated and will soon
be removed along with the need to define an install script.

This will remove a whole category of package manager
warnings about install scripts and "built" dependencies.

Most people don't need to build sharp from source, but for
those that do, a suitable method is now something like:

$ npm install package-that-depends-on-sharp
$ npm explore sharp -- npm run build

biome.json

@@ -1,5 +1,5 @@
 {
-  "$schema": "https://biomejs.dev/schemas/2.2.4/schema.json",
+  "$schema": "https://biomejs.dev/schemas/2.2.5/schema.json",
   "vcs": {
     "enabled": true,
     "clientKind": "git",