chore: remove transactional annotation

[guqing]

What type of PR is this?

/kind cleanup
/area core
/milestone 2.19.x

What this PR does / why we need it:

移除事务注解避免对索引创建产生影响，原因参考改动中的方法注释

其中一点特别注意：
在执行 client.create(name, data) 方法后，会尝试进行 indexer.indexRecord 操作。但 indexRecord 可能会因唯一索引中存在重复键而导致 indexRecord 失败，索引创建也会随之失败。为确保索引与数据的一致性，此时应回滚由 client.create(name, data) 对数据产生的影响，因此除非找到更佳的一致性问题解决方案，否则暂时不能移除此处的手动事务操作。

 return client.create(name, version, data)
                .map(updated -> converter.convertFrom(type, updated))
                .doOnNext(extension -> indexer.indexRecord(convertToRealExtension(extension)))
                .as(transactionalOperator::transactional);

将变更传递给 extension watcher 是在 doCreate 或 doUpdate 成功之后才会被处理，因此这里的事务回滚不会对 watcher 造成影响

Does this PR introduce a user-facing change?

None

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 58.23%. Comparing base (6cd8dc8) to head (383490f).
Report is 3 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #6492      +/-   ##
============================================
+ Coverage     58.18%   58.23%   +0.05%     
  Complexity     3774     3774              
============================================
  Files           651      651              
  Lines         22125    22125              
  Branches       1538     1538              
============================================
+ Hits          12873    12885      +12     
+ Misses         8641     8631      -10     
+ Partials        611      609       -2     

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[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[JohnNiang]

/lgtm

[f2c-ci-robot]

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