Fix a Kotlin test timing issue due to slow starting coroutines

[jponge]

No description provided.

[codecov]

Codecov Report

Merging #824 (75f9166) into main (6dd29ab) will increase coverage by 0.01%.
The diff coverage is 100.00%.

@@             Coverage Diff              @@
##               main     #824      +/-   ##
============================================
+ Coverage     89.12%   89.14%   +0.01%     
- Complexity     3055     3058       +3     
============================================
  Files           383      383              
  Lines         12131    12133       +2     
  Branches       1525     1528       +3     
============================================
+ Hits          10812    10816       +4     
- Misses          700      701       +1     
+ Partials        619      616       -3     

Impacted Files	Coverage Δ
...smallrye/mutiny/infrastructure/Infrastructure.java	68.88% <100.00%> (+0.34%)	⬆️
...utiny/operators/multi/MultiWindowOnDurationOp.java	65.71% <0.00%> (-4.29%)	⬇️
...java/io/smallrye/mutiny/helpers/Subscriptions.java	79.00% <0.00%> (-2.77%)	⬇️
.../io/smallrye/mutiny/helpers/queues/DrainUtils.java	82.22% <0.00%> (ø)
...operators/multi/builders/CollectionBasedMulti.java	93.54% <0.00%> (ø)
...mallrye/mutiny/operators/multi/MultiFlatMapOp.java	85.10% <0.00%> (+0.30%)	⬆️
...allrye/mutiny/operators/uni/UniAndCombination.java	89.88% <0.00%> (+1.12%)	⬆️
...perators/multi/processors/SerializedProcessor.java	94.05% <0.00%> (+1.98%)	⬆️
...mallrye/mutiny/operators/multi/FlatMapManager.java	95.83% <0.00%> (+2.77%)	⬆️
...subscription/SwitchableSubscriptionSubscriber.java	97.60% <0.00%> (+4.00%)	⬆️
... and 1 more