ObservableQuery and QueryInfo stays forever on skip:true (#7205)

Fixes #7206.

src/core/ObservableQuery.ts

@@ -625,6 +625,8 @@ once, rather than every time you call fetchMore.`);
   }
 
   private tearDownQuery() {
+    if (this.isTornDown) return;
+
     const { queryManager } = this;
 
     if (this.reobserver) {

src/react/data/QueryData.ts

@@ -471,6 +471,8 @@ export class QueryData<TData, TVariables> extends OperationData {
     if (this.currentSubscription) {
       this.currentSubscription.unsubscribe();
       delete this.currentSubscription;
+    } else if (this.currentObservable && this.getOptions().skip) {
+      this.currentObservable["tearDownQuery"]();
     }
   }
 

src/react/hooks/__tests__/useQuery.test.tsx

@@ -2225,6 +2225,30 @@ describe('useQuery Hook', () => {
         expect(renderCount).toBe(3);
       }).then(resolve, reject);
     });
+
+    it('should tear down the query if `skip` is `true`', () => {
+      const client = new ApolloClient({
+        link: new ApolloLink(),
+        cache: new InMemoryCache()
+      });
+
+      const Component = () => {
+        useQuery(CAR_QUERY, { skip: true });
+        return null;
+      };
+
+      const app = render(
+        <ApolloProvider client={client}>
+          <Component />
+        </ApolloProvider>
+      );
+
+      expect(client['queryManager']['queries'].size).toBe(1);
+
+      app.unmount();
+
+      expect(client['queryManager']['queries'].size).toBe(0);
+    });
   });
 
   describe('Previous data', () => {