Make jsi::Object constructor explicit (#53521)

Summary:
Pull Request resolved: #53521

Make `jsi::Object` constructor explicit, so its creation is explicit and
intentional. This prevents any sad foot-gun of constructing an Object
implicitly from a Runtime, which is certainly not a JS object.

Changelog: [Internal]

Reviewed By: avp

Differential Revision: D81274439

fbshipit-source-id: 5a9d9907f9deff7625dcff9c1072eb135ab7840e

Author: tsaichien

packages/react-native/ReactCommon/jsi/jsi/jsi.h

@@ -914,7 +914,7 @@ class JSI_EXPORT Object : public Pointer {
   Object& operator=(Object&& other) = default;
 
   /// Creates a new Object instance, like '{}' in JS.
-  Object(Runtime& runtime) : Object(runtime.createObject()) {}
+  explicit Object(Runtime& runtime) : Object(runtime.createObject()) {}
 
   static Object createFromHostObject(
       Runtime& runtime,