Bump OTel to version 1.21.0

[cescoffier]

No description provided.

[codecov-commenter]

Codecov Report

Merging #2023 (029dff0) into main (89918f6) will increase coverage by 0.02%.
The diff coverage is 73.33%.

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #2023      +/-   ##
============================================
+ Coverage     77.35%   77.38%   +0.02%     
- Complexity     3464     3474      +10     
============================================
  Files           293      294       +1     
  Lines         11637    11652      +15     
  Branches       1486     1487       +1     
============================================
+ Hits           9002     9017      +15     
- Misses         1938     1942       +4     
+ Partials        697      693       -4     

Impacted Files	Coverage Δ
...o/smallrye/reactive/messaging/mqtt/MqttSource.java	84.78% <ø> (-0.33%)	⬇️
...active/messaging/providers/helpers/MultiUtils.java	44.82% <21.05%> (-45.18%)	⬇️
...ye/reactive/messaging/providers/wiring/Wiring.java	92.96% <80.00%> (ø)
...mallrye/reactive/messaging/amqp/AmqpConnector.java	83.05% <100.00%> (ø)
...llrye/reactive/messaging/kafka/KafkaConnector.java	89.47% <100.00%> (ø)
...llrye/reactive/messaging/kafka/impl/KafkaSink.java	94.03% <100.00%> (-0.12%)	⬇️
...rye/reactive/messaging/kafka/impl/KafkaSource.java	86.09% <100.00%> (+0.76%)	⬆️
...eactive/messaging/providers/ProcessorMediator.java	91.45% <100.00%> (ø)
...eactive/messaging/providers/PublisherMediator.java	78.57% <100.00%> (ø)
...messaging/providers/StreamTransformerMediator.java	94.20% <100.00%> (+0.17%)	⬆️
... and 15 more