Skip particle passes in Ogre2GpuRays if there are no particles in the scene

[iche033]

🦟 Bug fix

Summary

Improve Ogre2GpuRays performance in the same way as done in #971 for Ogre2DepthCamera. Added execution mask to skip the particle passes when there are no particles in the scene

The time taken for a lidar (160 degrees FOV and 640 samples) to do a render update is shown below. The speedup is roughly ~1ms (30%). I also included the ogre1.x implementation for comparison. The ogre 1.x implementation is still faster (~5.5x) than the ogre2.x implementation

Checklist

• Signed all commits for DCO
• Added tests
• Updated documentation (as needed)
• Updated migration guide (as needed)
• Consider updating Python bindings (if the library has them)
• codecheck passed (See contributing)
• All tests passed (See test coverage)
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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 75.62%. Comparing base (4f01a66) to head (70f5003).

Additional details and impacted files

@@                Coverage Diff                @@
##           gz-rendering8     #973      +/-   ##
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+ Coverage          75.59%   75.62%   +0.02%     
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  Files                177      177              
  Lines              16934    16952      +18     
=================================================
+ Hits               12802    12820      +18     
  Misses              4132     4132              

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