Pipe: Fixed the bug that the parent class loader may wrongly load ext pipe plugins

[Caideyipi]

Description

As the title said.

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This PR has:

• been self-reviewed.
  • concurrent read
  • concurrent write
  • concurrent read and write
• added documentation for new or modified features or behaviors.
• added Javadocs for most classes and all non-trivial methods.
• added or updated version, license, or notice information
• added comments explaining the "why" and the intent of the code wherever would not be obvious
  for an unfamiliar reader.
• added unit tests or modified existing tests to cover new code paths, ensuring the threshold
  for code coverage.
• added integration tests.
• been tested in a test IoTDB cluster.

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Key changed/added classes (or packages if there are too many classes) in this PR

[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 SonarQube Cloud

[codecov]

Codecov Report

❌ Patch coverage is 94.44444% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 39.97%. Comparing base (b7eb193) to head (9fef726).
⚠️ Report is 9 commits behind head on master.

Files with missing lines	Patch %	Lines
...pe/agent/plugin/service/PipePluginClassLoader.java	94.44%	1 Missing ⚠️

Additional details and impacted files

@@ Coverage Diff @@## master #17580 +/- ##
=========================================
Coverage 39.96% 39.97% Complexity 2547 2547 =========================================
Files 5175 5175 Lines 348396 348433 +37 Branches 44531 44535 +4 =========================================
+ Hits 139239 139286 +47 + Misses 209157 209147 -10 

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