chore: z.object changeset (#5826)

Co-authored-by: bholmesdev <bholmesdev@gmail.com>

.changeset/quiet-actors-agree.md

@@ -0,0 +1,20 @@
+---
+'astro': minor
+---
+
+Allow Zod objects, unions, discriminated unions, intersections, and transform results as content collection schemas.
+
+#### Migration
+
+Astro requires a `z.object(...)` wrapper on all content collection schemas. Update your content collections config like so:
+
+```diff
+// src/content/config.ts
+import { z, defineCollection } from 'astro:content';
+
+const blog = defineCollection({
+- schema: {
++ schema: z.object({
+  ...
+})
+```