Distribute prebuilt binaries via the npm registry #3750

- Remove all custom download logic for prebuilt binaries
- Add scripts to populate package contents
- Specify minimum versions of common package managers
- Remove sharp.vendor runtime API as no-longer relevant
- Update installation docs and issue templates

npm/darwin-x64/package.json

@@ -0,0 +1,39 @@
+{
+  "name": "@sharpen/sharp-darwin-x64",
+  "version": "0.0.1-alpha.1",
+  "description": "Prebuilt sharp for use with macOS x64",
+  "homepage": "https://sharp.pixelplumbing.com",
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/lovell/sharp.git",
+    "directory": "npm/darwin-x64"
+  },
+  "license": "Apache-2.0",
+  "funding": {
+    "url": "https://opencollective.com/libvips"
+  },
+  "preferUnplugged": true,
+  "optionalDependencies": {
+    "@sharpen/sharp-libvips-darwin-x64": "0.0.1-alpha.1"
+  },
+  "files": [
+    "lib"
+  ],
+  "exports": {
+    "./sharp.node": "./lib/sharp-darwin-x64.node",
+    "./package": "./package.json"
+  },
+  "engines": {
+    "node": "^18.17.0 || ^20.3.0 || >=21.0.0",
+    "npm": ">=9.6.5",
+    "yarn": ">=3.2.0",
+    "pnpm": ">=7.1.0",
+    "glibc": ">=2.26"
+  },
+  "os": [
+    "darwin"
+  ],
+  "cpu": [
+    "x64"
+  ]
+}