fix: make sharp an optional dep

.changeset/sweet-icons-stare.md

@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Installing will no longer fail when Sharp can't be installed

packages/astro/package.json

@@ -162,7 +162,6 @@
     "resolve": "^1.22.4",
     "semver": "^7.5.4",
     "server-destroy": "^1.0.1",
-    "sharp": "^0.32.5",
     "shiki": "^0.14.3",
     "string-width": "^6.1.0",
     "strip-ansi": "^7.1.0",
@@ -176,6 +175,9 @@
     "yargs-parser": "^21.1.1",
     "zod": "3.21.1"
   },
+  "optionalDependencies": {
+    "sharp": "^0.32.5"
+  },
   "devDependencies": {
     "@astrojs/check": "^0.1.0",
     "@playwright/test": "^1.37.1",

packages/astro/src/core/errors/errors-data.ts

@@ -814,8 +814,9 @@ export const InvalidDynamicRoute = {
 export const MissingSharp = {
 	name: 'MissingSharp',
 	title: 'Could not find Sharp.',
-	message: 'Could not find Sharp. Please install Sharp (`sharp`) manually into your project.',
-	hint: "See Sharp's installation instructions for more information: https://sharp.pixelplumbing.com/install. If you are not relying on `astro:assets` to optimize, transform, or process any images, you can configure a passthrough image service instead of installing Sharp. See https://docs.astro.build/en/reference/errors/missing-sharp for more information.",
+	message:
+		'Could not find Sharp. Please install Sharp (`sharp`) manually into your project or migrate to another image service.',
+	hint: "See Sharp's installation instructions for more information: https://sharp.pixelplumbing.com/install. If you are not relying on `astro:assets` to optimize, transform, or process any images, you can configure a passthrough image service instead of installing Sharp. See https://docs.astro.build/en/reference/errors/missing-sharp for more information.\n\nSee https://docs.astro.build/en/guides/images/#default-image-service for more information on how to migrate to another image service.",
 };
 // No headings here, that way Vite errors are merged with Astro ones in the docs, which makes more sense to users.
 // Vite Errors - 4xxx