Fix crash when setting Anisotropic property after Global Illumination disabled by adding validity checks for GI and enabled state

[XINJIANGMO]

🦟 Bug fix

Fixes #3083

Summary

If we switch enabled from checked state to unchecked state , plugin will release gi object. If now we uncheck Anisotropic property , this plugin will set lightingDirty to true and call this->dataPtr->gi->SetAnisotropic(...).

Reproduce

1. gz sim shapes.sdf
2. from the plugin dropdown, select the Global Illumination VCT plugin
3. check Enabled
4. uncheck Enabled
5. uncheck Anisotropic

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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[azeey]

I wouldn't consider this to be a critical bug since (1) GI is not a commonly used feature (2) you have to do those specific steps to run into the issue. So let's hold off from merging. Thanks for the fix @XINJIANGMO though!

[iche033]

I wouldn't consider this to be a critical bug since (1) GI is not a commonly used feature (2) you have to do those specific steps to run into the issue. So let's hold off from merging. Thanks for the fix @XINJIANGMO though!

This is targeted at main so I think it should be fine? We can do the backport to jetty but hold off from merging?

[azeey]

This is targeted at main so I think it should be fine? We can do the backport to jetty but hold off from merging?

It will be difficult to remember which PRs we need to backport if we don't do it immediately. I guess we can create the backport PRs to gz-sim10 but not merge it. But that requires all the maintainers to be aware of this new way of doing things, so I'd prefer not to merge it for now until we have a discussion and have a clear policy about PRs targetting main during the code freeze.