Rendering tests segfault if the engine is unloaded

[iche033]

Environment

• OS Version: Ubuntu 22.04

• Source or binary build? source, gz-gui7

• If this is a GUI or sensor rendering bug, describe your GPU and rendering system. Otherwise delete this section.

  • Rendering plugin: ogre2.

    • GUI rendering error.

  • Generally, mention all circumstances that might affect rendering capabilities:

    • running on jammy github actions (only happens on jammy)

Description

• Expected behavior: Test exists successfully
• Actual behavior: Tests segfault when there is an rendering::unloadEngine call

Steps to reproduce

Add the following call to unload the render engine in the transport _scene_manager integration test before the tests exists

EXPECT_TRUE(rendering::unloadEngine(engine->Name()));

See the test fail due to segfault on jammy github actions. The segfault happens when the tests exit (after successfully unloading the engine). The crash could be coming from the destructor of a rendering class.

See #561 that removes these unload engine calls in order to get the CI green.