Use Thread#join without a duration

* Time varies a lot in CI, using a duration is making tests more flaky.

Author: eregon

test/lint/streams.rb

@@ -427,7 +427,7 @@ def test_xread_does_not_raise_timeout_error_when_the_block_option_is_zero_msec
       Thread.pass until prepared
       redis2 = init _new_client
       redis2.xadd('s1', { f: 'v1' }, id: '0-1')
-      thread.join(3)
+      thread.join
 
       assert_equal(['v1'], actual.fetch('s1').map { |i| i.last['f'] })
     end

test/redis/publish_subscribe_test.rb

@@ -19,7 +19,7 @@ def teardown
       end
       redis.close
       begin
-        thread.join(2) or warn("leaked thread")
+        thread.join
       rescue RedisClient::ConnectionError
       end
     end
@@ -296,7 +296,7 @@ def test_unsubscribe_from_another_thread
     assert_empty @messages
 
     @subscribed_redis.unsubscribe # this shouldn't block
-    refute_nil thread.join(2)
+    thread.join
     assert_equal true, @unsubscribed
   end
 
@@ -329,7 +329,7 @@ def test_subscribe_from_another_thread
     @subscribed_redis.unsubscribe(channel_name)
     @subscribed_redis.unsubscribe # this shouldn't block
 
-    refute_nil thread.join(2)
+    thread.join
     expected = [
       ["subscribed", channel_name],
       ["message", channel_name, "test"],