Fix static method in file header (#29118)

Summary:
I have looked into recent commits and found a typical mistake when static is used in .h file.
Here static is not necessary. See link: https://stackoverflow.com/questions/780730/c-c-static-function-in-header-file-what-does-it-mean

## Changelog
Changelog: [Internal] Fabric-specific internal change.
Pull Request resolved: https://github.com/facebook/react-native/pull/29118

Reviewed By: sammy-SC

Differential Revision: D22039305

Pulled By: shergin

fbshipit-source-id: 7078e716166067dd1e94cbb84200a1235283c978

ReactCommon/utils/ManagedObjectWrapper.h

@@ -27,18 +27,7 @@ namespace detail {
  * A custom deleter used for the deallocation of Objective-C managed objects.
  * To be used only by `wrapManagedObject`.
  */
-static void wrappedManagedObjectDeleter(void *cfPointer) noexcept
+void wrappedManagedObjectDeleter(void *cfPointer) noexcept;
-{
-  // A shared pointer does call custom deleter on `nullptr`s.
-  // This is somewhat counter-intuitively but makes sense considering the type-erasured nature of shared pointer and an
-  // aliasing constructor feature. `CFRelease` crashes on null pointer though. Therefore we must check for this case
-  // explicitly.
-  if (cfPointer == NULL) {
-    return;
-  }
-
-  CFRelease(cfPointer);
-}
 
 }
 

ReactCommon/utils/ManagedObjectWrapper.mm

@@ -10,6 +10,27 @@
 #if defined(__OBJC__) && defined(__cplusplus)
 #if TARGET_OS_MAC && TARGET_OS_IPHONE
 
+namespace facebook {
+namespace react {
+namespace detail {
+
+void wrappedManagedObjectDeleter(void *cfPointer) noexcept
+{
+  // A shared pointer does call custom deleter on `nullptr`s.
+  // This is somewhat counter-intuitively but makes sense considering the type-erasured nature of shared pointer and an
+  // aliasing constructor feature. `CFRelease` crashes on null pointer though. Therefore we must check for this case
+  // explicitly.
+  if (cfPointer == NULL) {
+    return;
+  }
+
+  CFRelease(cfPointer);
+}
+
+} // namespace detail
+} // namespace react
+} // namespace facebook
+
 @implementation RCTInternalGenericWeakWrapper
 @end