fix: backup maybe failed when the selectedPodPolicy is all

[wangyelei]

No description provided.

[apecloud-bot]

Auto Cherry-pick Instructions

Usage:
  - /nopick: Not auto cherry-pick when PR merged.
  - /pick: release-x.x [release-x.x]: Auto cherry-pick to the specified branch when PR merged.

Example:
  - /nopick
  - /pick release-1.0

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 59.84%. Comparing base (c4d401d) to head (f5c5cf2).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #9556      +/-   ##
==========================================
+ Coverage   59.83%   59.84%   +0.01%     
==========================================
  Files         518      518              
  Lines       56320    56321       +1     
==========================================
+ Hits        33699    33706       +7     
- Misses      19600    19604       +4     
+ Partials     3021     3011      -10     

Flag	Coverage Δ
unittests	59.84% <100.00%> (+0.01%)	⬆️

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[apecloud-bot]

/cherry-pick release-1.0

[apecloud-bot]

/cherry-pick release-0.9

[apecloud-bot]

🤖 says: cherry pick action finished successfully 🎉!
See: https://github.com/apecloud/kubeblocks/actions/runs/16439039300

[apecloud-bot]

🤖 says: cherry pick action finished successfully 🎉!
See: https://github.com/apecloud/kubeblocks/actions/runs/16439038245