fix(@angular-devkit/build-angular): alllow OPTIONS requests to be proxied when using vite

This commit fixes an issue were `OPTIONS` requests were not being proxied when using Vite dev-server

Closes #26782

(cherry picked from commit 771fdcd)

Author: alan-agius4

packages/angular_devkit/build_angular/src/builders/dev-server/vite-server.ts

@@ -483,6 +483,10 @@ export async function setupServer(
       open: serverOptions.open,
       headers: serverOptions.headers,
       proxy,
+      cors: {
+        // Allow preflight requests to be proxied.
+        preflightContinue: true,
+      },
       // File watching is handled by the build directly. `null` disables file watching for Vite.
       watch: null,
       fs: {