Remove flaky test

Fixes #4331

spec/unit/room.spec.ts

@@ -1394,22 +1394,6 @@ describe("Room", function () {
                 expect(name).toEqual(userB);
             });
         });
-
-        it("recalculates in acceptable time without heroes", function () {
-            for (let i = 0; i < 5000; i++) {
-                addMember(`@person${i}:bar`, KnownMembership.Join, { name: `Person ${i % 20} ${i % 10} ${i % 3}` });
-            }
-
-            // This isn't a real performance test and has plenty of headroom because github
-            // runners don't offer any kind of speed consistency guarantee, but this should at
-            // least assert that the perf doesn't suddenly become n^2.
-            const start = performance.now();
-            for (let i = 0; i < 50; i++) {
-                room.recalculate();
-            }
-            const duration = performance.now() - start;
-            expect(duration).toBeLessThan(200);
-        });
     });
 
     describe("receipts", function () {