[2.7] Improve method callback test

[kylixs]

What is the purpose of the change

Improve MethodConfigCallbackTest, tests transaction of callback method #8098

Brief changelog

Verifying this change

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.
• Each commit in the pull request should have a meaningful subject line and body.
• Write a pull request description that is detailed enough to understand what the pull request does, how, and why.
• 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.
• GitHub Actions works fine on your own branch.
• If this contribution is large, please follow the Software Donation Guide.

[codecov-commenter]

Codecov Report

Merging #8120 (f7d10a6) into master (c8cefee) will decrease coverage by 0.74%.
The diff coverage is n/a.

@@             Coverage Diff              @@
##             master    #8120      +/-   ##
============================================
- Coverage     61.15%   60.41%   -0.75%     
+ Complexity      489      488       -1     
============================================
  Files          1090     1090              
  Lines         43937    43937              
  Branches       6418     6418              
============================================
- Hits          26870    26543     -327     
- Misses        14089    14412     +323     
- Partials       2978     2982       +4     

Impacted Files	Coverage Δ
...ookeeper/ZookeeperDynamicConfigurationFactory.java	0.00% <0.00%> (-100.00%)	⬇️
...gcenter/wrapper/CompositeDynamicConfiguration.java	0.00% <0.00%> (-73.34%)	⬇️
...fig/configcenter/TreePathDynamicConfiguration.java	25.71% <0.00%> (-60.01%)	⬇️
...pport/zookeeper/ZookeeperDynamicConfiguration.java	0.00% <0.00%> (-57.15%)	⬇️
.../dubbo/metadata/report/MetadataReportInstance.java	12.50% <0.00%> (-40.63%)	⬇️
.../configcenter/support/zookeeper/CacheListener.java	0.00% <0.00%> (-28.58%)	⬇️
...ng/transport/dispatcher/all/AllChannelHandler.java	68.96% <0.00%> (-20.69%)	⬇️
...mmon/config/configcenter/DynamicConfiguration.java	68.18% <0.00%> (-18.19%)	⬇️
...gistry/client/migration/MigrationRuleListener.java	55.88% <0.00%> (-17.65%)	⬇️
...ient/metadata/store/RemoteMetadataServiceImpl.java	38.59% <0.00%> (-17.55%)	⬇️
... and 39 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update c8cefee...f7d10a6. Read the comment docs.