Do not create light visuals on server side (backport #2888)

[mergify]

🦟 Bug fix

Fixes gazebosim/gz-rendering#1122

Summary

Light visuals (green lines) were always created, even on server side where sensors are enabled. Looks like a regression introduced in #1818. This PR adds the if (!this->dataPtr->enableSensors) check back to make sure we only create light visuals if sensors are not enabled.

This was causing segmentation camera to crash if the light visual is in its view (see gazebosim/gz-rendering#1122).

To Test:

Apply this diff below to segmentation_camera.sdf to position the directional light in the view of the segmentation camera. With the changes in this PR, gz sim should no longer crash.

diff --git a/examples/worlds/segmentation_camera.sdf b/examples/worlds/segmentation_camera.sdf
index c5f4df7de..10cf19963 100644
--- a/examples/worlds/segmentation_camera.sdf
+++ b/examples/worlds/segmentation_camera.sdf
@@ -158,7 +158,8 @@
 
     <light type="directional" name="sun">
       <cast_shadows>true</cast_shadows>
-      <pose>0 0 10 0 0 0</pose>
+      <visualize>true</visualize>
+      <pose>0 0 2 0 0 0</pose>
       <diffuse>0.8 0.8 0.8 1</diffuse>
       <specular>0.2 0.2 0.2 1</specular>

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)
• While waiting for a review on your PR, please help review another open pull request to support the maintainers

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This is an automatic backport of pull request #2888 done by [Mergify](https://mergify.com).