🐛(frontend) fix infinite loader for product widget

This bug was occuring when clicking on the button "Login to purchase"
causing a removal of existing react-query queries. This was caused by
premature removal of the pending useCourse query which was never notified
that it had been removed during its loading, resulting in an infinite
loading state.

src/frontend/js/data/SessionProvider/JoanieSessionProvider.tsx

@@ -123,7 +123,7 @@ const JoanieSessionProvider = ({ children }: React.PropsWithChildren<any>) => {
   useEffect(() => {
     // When user is updated, session queries should be invalidated.
     if (previousUserState !== user) {
-      queryClient.removeQueries({
+      queryClient.invalidateQueries({
         predicate: (query: any) =>
           query.options.queryKey.includes('user') && query.options.queryKey.length > 1,
       });

src/frontend/js/hooks/useCourse.ts

@@ -5,8 +5,8 @@
 import { useQuery, useQueryClient } from '@tanstack/react-query';
 import { useJoanieApi } from 'data/JoanieApiProvider';
 import useLocalizedQueryKey from 'utils/react-query/useLocalizedQueryKey';
-import { REACT_QUERY_SETTINGS } from 'settings';
 import { useSession } from 'data/SessionProvider';
+import { REACT_QUERY_SETTINGS } from 'settings';
 
 /**
  * Joanie Api hook to retrieve information of a course for the given code.
@@ -26,7 +26,6 @@ export const useCourse = (code: string) => {
     refetch,
     isLoading,
   } = useQuery(QUERY_KEY, () => API.courses.get(code), {
-    enabled: user !== undefined,
     staleTime: user
       ? REACT_QUERY_SETTINGS.staleTimes.sessionItems
       : REACT_QUERY_SETTINGS.staleTimes.default,