Get pubsub numpat working

This was a cherry-pick of e08b42616b

Only the unit test was needed to be back-ported

Tests/RediStackIntegrationTests/Commands/PubSubCommandsTests.swift

@@ -189,6 +189,14 @@ final class RedisPubSubCommandsTests: RediStackIntegrationTestCase {
         self.waitForExpectations(timeout: 1)
     }
 
+    func test_pubSubNumpat() throws {
+        let queryConnection = try self.makeNewConnection()
+        defer { try? queryConnection.close().wait() }
+
+        let numPat = try queryConnection.patternSubscriberCount().wait()
+        XCTAssertGreaterThanOrEqual(numPat, 0)
+    }
+
     func test_pubSubChannels() throws {
         let fn = #function
         let subscriber = try self.makeNewConnection()