Grl webgl ubo fix

[RolandCsibrei]

Fixing this issue: https://forum.babylonjs.com/t/after-upgrade-to-7-39-1-cannot-add-an-uniform-after-ubo-has-been-created/55296

[bjsplat]

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[bjsplat]

Snapshot stored with reference name:
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Test environment:
https://snapshots-cvgtc2eugrd3cgfd.z01.azurefd.net/refs/pull/15981/merge/index.html

To test a playground add it to the URL, for example:

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[bjsplat]

Visualization tests for WebGL 1 have failed. If some tests failed because the snapshots do not match, the report can be found at

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[bjsplat]

Visualization tests for WebGPU (Experimental)

https://snapshots-cvgtc2eugrd3cgfd.z01.azurefd.net/refs/pull/15981/merge/testResults/webgpuplaywright/index.html

[bjsplat]

WebGL2 visualization test reporter:

https://snapshots-cvgtc2eugrd3cgfd.z01.azurefd.net/refs/pull/15981/merge/testResults/webgl2playwright/index.html