Stringify context as SomeContext instead of SomeContext.Provider (#33507)

This matches the change in React 19 to use `<SomeContext>` as the
preferred way to provide a context.

packages/react-reconciler/src/__tests__/ReactLazy-test.internal.js

@@ -941,7 +941,7 @@ describe('ReactLazy', () => {
       </Suspense>,
     );
     await waitForThrow(
-      'Element type is invalid. Received a promise that resolves to: Context.Provider. ' +
+      'Element type is invalid. Received a promise that resolves to: Context. ' +
         'Lazy element type must resolve to a class or function.',
     );
   });

packages/react-reconciler/src/getComponentNameFromFiber.js

@@ -94,7 +94,7 @@ export default function getComponentNameFromFiber(fiber: Fiber): string | null {
       return getContextName(consumer._context) + '.Consumer';
     case ContextProvider:
       const context: ReactContext<any> = (type: any);
-      return getContextName(context) + '.Provider';
+      return getContextName(context);
     case DehydratedFragment:
       return 'DehydratedFragment';
     case ForwardRef:

packages/shared/getComponentNameFromType.js

@@ -106,7 +106,7 @@ export default function getComponentNameFromType(type: mixed): string | null {
         return 'Portal';
       case REACT_CONTEXT_TYPE:
         const context: ReactContext<any> = (type: any);
-        return getContextName(context) + '.Provider';
+        return getContextName(context);
       case REACT_CONSUMER_TYPE:
         const consumer: ReactConsumerType<any> = (type: any);
         return getContextName(consumer._context) + '.Consumer';