These tests have all failed in daily CI:
```
*** [err]: Blocking XREADGROUP for stream key that has clients blocked on stream - reprocessing command in tests/unit/type/stream-cgroups.tcl
Expected '1101' to be between to '1000' and '1100' (context: type eval line 23 cmd {assert_range [expr $end-$start] 1000 1100} proc ::test)
*** [err]: BLPOP unblock but the key is expired and then block again - reprocessing command in tests/unit/type/list.tcl
Expected '1101' to be between to '1000' and '1100' (context: type eval line 23 cmd {assert_range [expr $end-$start] 1000 1100} proc ::test)
*** [err]: BZPOPMIN unblock but the key is expired and then block again - reprocessing command in tests/unit/type/zset.tcl
Expected '1103' to be between to '1000' and '1100' (context: type eval line 23 cmd {assert_range [expr $end-$start] 1000 1100} proc ::test)
```
Increase the range to avoid failures, and improve the comment to be
clearer.
tests was introduced in #13004.
Signed-off-by: Ping Xie <pingxie@google.com>
fa1bba8619