Fix test failure due to differing reply format of XREADGROUP under RESP3 in MULTI

[sundb]

This test was introducted by #13251.
Normally we auto transform the reply format of XREADGROUP to array under RESP3 (see trasformer_funcs).
But when we execute XREADGROUP command in multi it can't work, which cause the new test failed.
The solution is to verity the reply of XREADGROUP in advance rather than in MULTI.

Failed validate schema CI: https://github.com/redis/redis/actions/runs/9025128323/job/24800285684

[sundb]

Fully CI only with flag --single unit/type/stream-cgroups passed: https://github.com/sundb/redis/actions/runs/9029242361

[guybe7]

@sundb aren't we running all tests with RESP3 by default when we verify the reply schema?

[sundb]

@guybe7 yes, but the test failed under RESP3, so I changed the test to always run under RESP3.
please note that i removed a {}.

[sundb]

the reason why i don't fix it under RESP2 is hello 2 doesn't work with flag --force-resp3.

[sundb]

@guybe7 I converted the map to array to consistency with RESP2.

[guybe7]

@sundb i don't understand why is XREADGROUP inside MULTI different from any other command inside MULTI

[sundb]

@guybe7 It's not different, we had never verify the command that reply a map inside the multi.
Not many commands reply a map.

[guybe7]

@sundb so we have a general problem with validating the reply schema of map-reply inside an EXEC reply?

[sundb]

@guybe7 yes, another alternative is to add an automatic verversion to exec command to convert all map replies into array,
i'm not sure it's worth.

[guybe7]

ok so the problem is that transform_response_if_needed won't work because argv[0] is EXEC and not any of the commands whose responses should be translated from RESP3 to RESP2 (see trasformer_funcs)

it's a deep issue, i think it's better to quick-fix it like this:

diff --git a/tests/unit/type/stream-cgroups.tcl b/tests/unit/type/stream-cgroups.tcl
index 2462a25ba..d5754d42b 100644
--- a/tests/unit/type/stream-cgroups.tcl
+++ b/tests/unit/type/stream-cgroups.tcl
@@ -1398,11 +1398,10 @@ start_server {
             $master del mystream
             $master xadd mystream 1-0 a b c d e f
             $master xgroup create mystream mygroup 0
-            $master xreadgroup group mygroup ryan count 1 streams mystream >
+            assert_equal [$master xreadgroup group mygroup ryan count 1 streams mystream >] {{mystream {{1-0 {a b c d e f}}}}}
             $master multi
             $master xreadgroup group mygroup ryan count 1 streams mystream 0
-            set reply [$master exec]
-            assert_equal $reply {{{mystream {{1-0 {a b c d e f}}}}}}
+            $master exec
         }
     }

[sundb]

@guybe7 thanks, apply your patch.