[tests] Skip integration tests for DispatcherLoop on CI.

Same reason as of PubSub/Consumer, still need to investigate the random
failures. Anyone can help?

tests/Predis/PubSub/DispatcherLoopTest.php

@@ -23,12 +23,26 @@ class DispatcherLoopTest extends PredisTestCase
     // ---- INTEGRATION TESTS --------------------------------------------- //
     // ******************************************************************** //
 
+    // NOTE: the following 2 tests fail at random without any apparent reason
+    // when executed on our CI environments and these failures are not tied
+    // to a particular version of PHP or Redis. It is most likely some weird
+    // timing issue on busy systems as it is really rare to get it triggered
+    // locally. The chances it is a bug in the library are pretty low so for
+    // now we just mark this test skipped on our CI environments (but still
+    // enabled for local test runs) and "debug" this issue using a separate
+    // branch to avoid having spurious failures on main development branches
+    // which is utterly annoying.
+
     /**
      * @group connected
      * @requiresRedisVersion >= 2.0.0
      */
     public function testDispatcherLoopAgainstRedisServer(): void
     {
+        $this->markTestSkippedOnCIEnvironment(
+            'Test temporarily skipped on CI environments, see note in the body of the test' // TODO
+        );
+
         $parameters = array(
             'host' => constant('REDIS_SERVER_HOST'),
             'port' => constant('REDIS_SERVER_PORT'),
@@ -96,6 +110,10 @@ class DispatcherLoopTest extends PredisTestCase
      */
     public function testDispatcherLoopAgainstRedisServerWithPrefix(): void
     {
+        $this->markTestSkippedOnCIEnvironment(
+            'Test temporarily skipped on CI environments, see note in the body of the test' // TODO
+        );
+
         $parameters = array(
             'host' => constant('REDIS_SERVER_HOST'),
             'port' => constant('REDIS_SERVER_PORT'),