Bloom luma calculation now in linear space

The luma calculation for bloom's Karis average (used for downsampling) has been corrected to use linear color space instead of non-linear sRGB space.

As a result, the intensity of the bloom effect may appear reduced, especially for colors with high saturation or those that were significantly affected by the previous non-linear calculation.

If your scene's bloom now appears too dim, you can:

• Increase the intensity field on the Bloom component.
• Increase the emissive strength of your materials.
• Adjust the prefilter settings in the Bloom component.