Fix CORS proxy for local development

- Remove deprecated curl_close() call (no-op since PHP 8.0, causes
  deprecation warning in PHP 8.5 that corrupts HTTP response)
- Skip POST requests in offline cache (Cache API doesn't support them)

Author: akirk

packages/playground/php-cors-proxy/cors-proxy.php

@@ -274,8 +274,6 @@ function(
 } else {
     @$relay_http_code_and_initial_headers_if_not_already_sent();
 }
-// Close cURL session
-curl_close($ch);
 
 // Only send chunked transfer encoding footer if we're using chunked encoding.
 // We need to manually send the footer when running in the PHP built-in server

packages/playground/remote/src/lib/offline-mode-cache.ts

@@ -11,11 +11,17 @@ const promisedOfflineModeCache = caches.open(LATEST_CACHE_NAME);
 
 export async function cacheFirstFetch(request: Request): Promise<Response> {
 	const offlineModeCache = await promisedOfflineModeCache;
-	const cachedResponse = await offlineModeCache.match(request, {
-		ignoreSearch: true,
-	});
-	if (cachedResponse) {
-		return cachedResponse;
+
+	// The Cache API only supports GET requests
+	const canCache = request.method === 'GET';
+
+	if (canCache) {
+		const cachedResponse = await offlineModeCache.match(request, {
+			ignoreSearch: true,
+		});
+		if (cachedResponse) {
+			return cachedResponse;
+		}
 	}
 
 	/**