fix: previous and next post links included hidden posts

[guqing]

What type of PR is this?

/kind bug
/area core
/milestone 2.19.x

What this PR does / why we need it:

修复文章的上一篇下一篇链接包含了隐藏分类下的文章

Does this PR introduce a user-facing change?

修复文章的上一篇下一篇链接包含了隐藏分类下的文章

[codecov]

Codecov Report

Attention: Patch coverage is 50.00000% with 3 lines in your changes missing coverage. Please review.

Project coverage is 58.21%. Comparing base (6cd8dc8) to head (dec4462).
Report is 2 commits behind head on main.

Files	Patch %	Lines
...un/halo/app/theme/finders/impl/PostFinderImpl.java	50.00%	3 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #6491      +/-   ##
============================================
+ Coverage     58.18%   58.21%   +0.03%     
  Complexity     3774     3774              
============================================
  Files           651      651              
  Lines         22125    22128       +3     
  Branches       1538     1538              
============================================
+ Hits          12873    12882       +9     
+ Misses         8641     8636       -5     
+ Partials        611      610       -1     

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[sonarqubecloud]

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]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: JohnNiang

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