WebGLBackend: Fix context parameter.

[Mugen87]

Related issue: -

Description

While trying to fix foveation with XRManager, I have noticed that the WebGL 2 rendering context is always created with antialias set to true. This has a side effect on XRManager as well as performance implications.

The antialias context parameter can always be set to false since the engine applies MSAA with custom renderbuffers.

With this change the framerate of the demanding SSAA demo improves from 45 to 53 FPS with a WebGL 2 backend (tested with Firefox). In fact, the overall performance of the WebGL backend has been improved since up to now the renderer applied MSAA on the fullscreen quad of the output pass.

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

	Before	After	Diff
WebGL	336.27 78.29	336.27 78.29	+0 B +0 B
WebGPU	512.43 142.36	512.43 142.37	+5 B +13 B
WebGPU Nodes	511.89 142.25	511.9 142.27	+5 B +13 B

🌳 Bundle size after tree-shaking

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

	Before	After	Diff
WebGL	465.25 112.13	465.25 112.13	+0 B +0 B
WebGPU	586.36 159.02	586.36 159.04	+5 B +24 B
WebGPU Nodes	541.74 148.57	541.75 148.59	+5 B +26 B