fix: a verified email can be reused

[guqing]

What type of PR is this?

/kind bug
/area core
/milestone 2.17.x

What this PR does / why we need it:

修复已验证邮箱可以重复的问题

如果出现多个重复的已验证邮箱，则只保留一个其他的设置为未验证

Does this PR introduce a user-facing change?

修复已验证邮箱可以重复的问题

[codecov]

Codecov Report

Attention: Patch coverage is 16.66667% with 40 lines in your changes missing coverage. Please review.

Project coverage is 56.40%. Comparing base (5fdf6c0) to head (519a78a).
Report is 239 commits behind head on main.

Files	Patch %	Lines
...ion/service/impl/EmailVerificationServiceImpl.java	0.00%	22 Missing ⚠️
.../app/core/extension/reconciler/UserReconciler.java	23.52%	12 Missing and 1 partial ⚠️
...lo/app/core/extension/service/UserServiceImpl.java	0.00%	4 Missing ⚠️
...ain/java/run/halo/app/infra/SchemeInitializer.java	80.00%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #6064      +/-   ##
============================================
- Coverage     56.91%   56.40%   -0.51%     
- Complexity     3319     3542     +223     
============================================
  Files           587      623      +36     
  Lines         18968    20990    +2022     
  Branches       1401     1482      +81     
============================================
+ Hits          10795    11839    +1044     
- Misses         7594     8549     +955     
- Partials        579      602      +23     

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[sonarqubecloud]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
0.2% Duplication on New Code

See analysis details on SonarCloud

[ruibaby]

/lgtm

[JohnNiang]

/approve

[f2c-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: JohnNiang

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