fix(autoware_pointcloud_preprocessor): fix potential double unlock in concatenate node

[vividf]

Description

This PR resolves a potential double unlock issue in the concatenate node. Previously, under certain conditions, the mutex could be unlocked twice, leading to undefined behavior and potential segmentation faults.

Related links

Note: This PR needs to rebase after #10074 is merged.

Parent Issue:

• Link

How was this PR tested?

• Tested with unit test.
• Tested with sample rosbag

Notes for reviewers

None.

Interface changes

None.

Effects on system behavior

None.

[github-actions]

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[codecov]

Codecov Report

Attention: Patch coverage is 62.06897% with 22 lines in your changes missing coverage. Please review.

Project coverage is 28.32%. Comparing base (bd84834) to head (d8c5033).
Report is 17 commits behind head on main.

Files with missing lines	Patch %	Lines
...processor/src/concatenate_data/cloud_collector.cpp	55.88%	8 Missing and 7 partials ⚠️
...oncatenate_data/concatenate_and_time_sync_node.cpp	70.83%	2 Missing and 5 partials ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main   #10082   +/-   ##
=======================================
  Coverage   28.32%   28.32%           
=======================================
  Files        1485     1486    +1     
  Lines      111090   111153   +63     
  Branches    43150    43171   +21     
=======================================
+ Hits        31466    31488   +22     
- Misses      76603    76640   +37     
- Partials     3021     3025    +4     

Flag	Coverage Δ		*Carryforward flag
differential	22.87% <62.06%> (?)
differential-cuda	20.64% <62.06%> (?)
total	28.31% <ø> (-0.02%)	⬇️	Carriedforward from 2f0ff33

*This pull request uses carry forward flags. Click here to find out more.

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