🧪 Add missing error test for AmbientBiotaDirector try-catch

[marko1olo]

🎯 What:
Added AmbientBiotaDirectorUploadTests.cs to test the try-catch block inside AmbientBiotaDirector.UploadPackedGpuInstances by purposely passing a disposed NativeArray.

📊 Coverage:
The test verifies that an invalid operation inside TryBuildGpuInstance will bubble up gracefully through the finally block where UnlockBufferAfterWrite ensures the buffer lock is released correctly.

✨ Result:
Improved test coverage on a highly critical fast-path function interacting with native buffers!

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PR created automatically by Jules for task 3203229797070636321 started by @marko1olo

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