WebGPURenderer: Fix linear filter textures w/o mipmaps

[RenaudRohlinger]

Related issue: #27071

Description

This PR addresses an issue in the WebGL backend where textures using linear filtering without mipmaps are rendered as completely black. The problem was caused by incorrect filtering, specifically the use of LinearMipmapLinearFilter instead of the appropriate filter for non-mipmapped textures.

For more context, an initial fix was made to address video textures breaking in the examples. However, this fix was only partial, as it did not cover all cases and still affects any linear filtered texture without mipmaps. More details in the related PR:
#27610

This contribution is funded by Utsubo

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

Filesize dev	Filesize PR	Diff
685.4 kB (169.7 kB)	685.4 kB (169.7 kB)	+0 B

🌳 Bundle size after tree-shaking

Minimal build including a renderer, camera, empty scene, and dependencies.

Filesize dev	Filesize PR	Diff
462 kB (111.4 kB)	462 kB (111.4 kB)	+0 B