refactor ServiceInstancesChangedListener equals and hashcode method

[finefuture]

What is the purpose of the change

The uniqueness of ServiceInstancesChangedListener should not be determined by listeners, because listeners is variable object, the same ServiceInstancesChangedListener object will be repeatedly added to the listener list, just use provider appname.

Brief changelog

Verifying this change

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Checklist

• Make sure there is a GitHub_issue field for the change (usually before you start working on it). Trivial changes like typos do not require a GitHub issue. Your pull request should address just this issue, without pulling in other changes - one PR resolves one issue.
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• Check if is necessary to patch to Dubbo 3 if you are work on Dubbo 2.7
• Write necessary unit-test to verify your logic correction, more mock a little better when cross module dependency exist. If the new feature or significant change is committed, please remember to add sample in dubbo samples project.
• Add some description to dubbo-website project if you are requesting to add a feature.
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[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 66.91%. Comparing base (e026b5b) to head (607430c).
⚠️ Report is 811 commits behind head on 3.2.

Additional details and impacted files

@@             Coverage Diff              @@
##                3.2   #12547      +/-   ##
============================================
- Coverage     69.76%   66.91%   -2.85%     
+ Complexity      318        2     -316     
============================================
  Files          3481     1763    -1718     
  Lines        165219    70861   -94358     
  Branches      27754    10158   -17596     
============================================
- Hits         115265    47419   -67846     
+ Misses        39950    18870   -21080     
+ Partials      10004     4572    -5432     

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[AlbumenJ]

@chickenlj PTAL

[AlbumenJ]

@CrazyHZM

[sonarqubecloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

80.0% Coverage
0.0% Duplication