Revert "feat(ci): add PR preview deployments"

This reverts commit 26df6a2.

Author: aaronpowell

.github/workflows/pr-preview.yml

@@ -1,13 +1,10 @@
 import sitemap from "@astrojs/sitemap";
 import { defineConfig } from "astro/config";
 
-// Support dynamic base path for PR previews via ASTRO_BASE env var
-const base = process.env.ASTRO_BASE || "/";
-
 // https://astro.build/config
 export default defineConfig({
   site: "https://github.github.io",
-  base: base,
+  base: "/",
   output: "static",
   integrations: [sitemap()],
   build: {