Increase timeout for expiry cluster tests (#12752)

Test recently added fails on timeout in valgrind in GH actions.

Locally with valgrind the test finishes within 1.5 sec(s). Couldn't find
any issue due to lack of reproducibility. Increasing the timeout and
adding an additional log to the test to understand how many keys
were left at the end.

tests/unit/expire.tcl

@@ -888,9 +888,11 @@ start_cluster 1 0 {tags {"expire external:skip cluster slow"}} {
         r psetex "{foo}0" 500 a
 
         # Verify all keys have expired
-        wait_for_condition 200 100 {
+        wait_for_condition 400 100 {
             [r dbsize] eq 0
         } else {
+            puts [r dbsize]
+            flush stdout
             fail "Keys did not actively expire."
         }
     } {} {needs:debug}