Use pragma once as header include guard

[J-Javan]

Description

The changes replace ifndef header include guards with pragma once.
See #882

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]

Codecov Report

Merging #1525 (ca1c561) into main (066e862) will decrease coverage by 0.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main    #1525      +/-   ##
==========================================
- Coverage   51.15%   51.14%   -0.00%     
==========================================
  Files         380      380              
  Lines       31758    31758              
==========================================
- Hits        16242    16239       -3     
- Misses      15516    15519       +3     

Impacted Files	Coverage Δ
...planner/include/joint_limits_copy/joint_limits.hpp	100.00% <ø> (ø)
...nclude/joint_limits_copy/joint_limits_rosparam.hpp	88.47% <ø> (ø)
...dl_kinematics_plugin/src/kdl_kinematics_plugin.cpp	75.36% <0.00%> (-1.07%)	⬇️

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[sjahr]

Looks good to me, thank you for your contribution!