[Cherry-Pick][CI] Optimize unittest and fix title format(#6464)

[EmmonsCurse]

Cherry-pick of #6464 (authored by @EmmonsCurse) to release/2.5.

devPR:#6464

---

Motivation

• The overall unit test runtime is relatively long, impacting CI cycle time and resource efficiency.
• The PR title format is inconsistent, which may affect automation logic and readability.

Modifications

• Optimized the unit test workflow to reduce unnecessary execution time and improve overall CI efficiency.
• Fixed the PR title generation logic to ensure a consistent and correct formatting pattern.

Usage or Command

N/A

Accuracy Tests

N/A

Checklist

• Add at least a tag in the PR title.
• Tag list: [[FDConfig],[APIServer],[Engine], [Scheduler], [PD Disaggregation], [Executor], [Graph Optimization], [Speculative Decoding], [RL], [Models], [Quantization], [Loader], [OP], [KVCache], [DataProcessor], [BugFix], [Docs], [CI], [Optimization], [Feature], [Benchmark], [Others], [XPU], [HPU], [GCU], [DCU], [Iluvatar], [Metax]]
• You can add new tags based on the PR content, but the semantics must be clear.
• Format your code, run pre-commit before commit.
• Add unit tests. Please write the reason in this PR if no unit tests.
• Provide accuracy results.
• If the current PR is submitting to the release branch, make sure the PR has been submitted to the develop branch, then cherry-pick it to the release branch with the [Cherry-Pick] PR tag.

[paddle-bot]

Thanks for your contribution!

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
⚠️ Please upload report for BASE (release/2.5@d36ff9e). Learn more about missing BASE report.

Additional details and impacted files

@@              Coverage Diff               @@
##             release/2.5    #6468   +/-   ##
==============================================
  Coverage               ?   68.32%           
==============================================
  Files                  ?      391           
  Lines                  ?    52736           
  Branches               ?     8211           
==============================================
  Hits                   ?    36033           
  Misses                 ?    14076           
  Partials               ?     2627           

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