WebGLRenderer: Remove WebGL 1 support.

[Mugen87]

Related issue: -

Description

We have deprecated WebGL 1 support in r153 which is almost a year ago. This PR eventually removes it from WebGLRenderer.

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

Filesize dev	Filesize PR	Diff
678.5 kB (168.6 kB)	669.6 kB (166.2 kB)	-8.93 kB

🌳 Bundle size after tree-shaking

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

Filesize dev	Filesize PR	Diff
458.8 kB (111.4 kB)	449.8 kB (108.8 kB)	-9.03 kB

[toji]

Quite the milestone! Congrats!

Now when we can start plotting the removal of WebGL 2 in favor of WebGPU? 😆

[mrdoob]

Let's regroup in 2034 😅

[alexkowel]

Just in case, if someone still needs WebGL 1.0, Verge3D will continue supporting the old standard for some time. Too many older iPhones are still around.