Support multiple service configuration listeners per service

[somiljain2006]

What is the purpose of the change?

It ensures that dynamic configuration listeners are handled correctly when the same service is exported multiple times. This change keeps all listeners for a service, applies their configurations together, and removes them correctly during unexport to avoid lost updates or memory leaks.

Fixed: #15803

Checklist

• Make sure there is a GitHub_issue field for the change.
• Write a pull request description that is detailed enough to understand what the pull request does, how, and why.
• Write necessary unit tests to verify your logic correction. If the new feature or significant change is committed, please remember to add a sample in the dubbo samples project.
• Make sure GitHub actions can pass. Why the workflow is failing and how to fix it?

[codecov-commenter]

Codecov Report

❌ Patch coverage is 89.47368% with 4 lines in your changes missing coverage. Please review.
✅ Project coverage is 59.65%. Comparing base (a3a35b5) to head (6a647bd).

Files with missing lines	Patch %	Lines
...e/dubbo/registry/integration/RegistryProtocol.java	89.47%	0 Missing and 4 partials ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##                3.3   #15925      +/-   ##
============================================
- Coverage     60.74%   59.65%   -1.10%     
+ Complexity    11702    11692      -10     
============================================
  Files          1938     1938              
  Lines         88694    88656      -38     
  Branches      13387    13385       -2     
============================================
- Hits          53879    52884     -995     
- Misses        29291    30311    +1020     
+ Partials       5524     5461      -63     

Flag	Coverage Δ
integration-tests-java21	32.32% <78.94%> (-0.06%)	⬇️
integration-tests-java8	32.45% <78.94%> (-0.09%)	⬇️
samples-tests-java21	32.05% <31.57%> (+0.03%)	⬆️
samples-tests-java8	29.74% <31.57%> (+0.04%)	⬆️
unit-tests-java11	?
unit-tests-java17	?
unit-tests-java21	?
unit-tests-java25	?
unit-tests-java8	59.05% <89.47%> (+0.01%)	⬆️

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