Unbreak Swift build - guard C++ header in #ifdef __cplusplus (#45941)

Summary:

Quick fix to avoid imports from Swift chaining to Objective-C++ headers. Will follow up with a redesign.

Changelog: [Internal]

Differential Revision: D60960077

packages/react-native/React/DevSupport/RCTInspectorNetworkHelper.h

@@ -5,10 +5,12 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-#import <jsinspector-modern/ReactCdp.h>
-
 #import <Foundation/Foundation.h>
 
+#ifdef __cplusplus
+
+#import <jsinspector-modern/ReactCdp.h>
+
 typedef facebook::react::jsinspector_modern::NetworkRequestListener RCTInspectorNetworkListener;
 
 typedef facebook::react::jsinspector_modern::ScopedExecutor<RCTInspectorNetworkListener> RCTInspectorNetworkExecutor;
@@ -23,3 +25,5 @@ typedef facebook::react::jsinspector_modern::LoadNetworkResourceRequest RCTInspe
 - (void)loadNetworkResourceWithParams:(const RCTInspectorLoadNetworkResourceRequest &)params
                              executor:(RCTInspectorNetworkExecutor)executor;
 @end
+
+#endif