fix: explicitly add the same namespace as the parent node

[KazuyaOguma18]

Description

Problem

When launching the move_group node with a namespace and running moveit_py within a node that has the same namespace, the moveit_simple_controller_manager lacked a namespace. As a result, the robot could not operate because the action for trajectory execution was missing the necessary namespace.

Solution

Explicitly added the parent node's namespace.

Checklist

• Required by CI: Code is auto formatted using clang-format
• Extend the tutorials / documentation reference
• Document API changes relevant to the user in the MIGRATION.md notes
• Create tests, which fail without this PR reference
• Include a screenshot if changing a GUI
• While waiting for someone to review your request, please help review another open pull request to support the maintainers

[codecov-commenter]

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Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 45.84%. Comparing base (83d05ae) to head (ffa3c14).

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Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3360      +/-   ##
==========================================
- Coverage   46.25%   45.84%   -0.41%     
==========================================
  Files         717      717              
  Lines       62596    62577      -19     
  Branches     7568     7564       -4     
==========================================
- Hits        28947    28681     -266     
- Misses      33482    33729     +247     
  Partials      167      167              

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[sea-bass]

Thank you! A small formatting fix is needed, but otherwise looks good.