WebGLBackend: Only invalidate framebuffers on supported devices.

[Mugen87]

Fixed #30589.

Description

The WebGL backend only calls gl.invalidateSubFramebuffer() or gl.invalidateFramebuffer() on supported devices with this OR. That are only Quest devices so far.

This rule is already in place for WebGLRenderer and now adapted here. Otherwise there are issue with MSAA on certain hardware.

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

	Before	After	Diff
WebGL	336.65 78.39	336.65 78.39	+0 B +0 B
WebGPU	522.34 145	522.53 145.06	+194 B +62 B
WebGPU Nodes	521.8 144.89	522 144.96	+194 B +62 B

🌳 Bundle size after tree-shaking

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

	Before	After	Diff
WebGL	465.7 112.26	465.7 112.26	+0 B +0 B
WebGPU	592.81 160.62	593 160.69	+194 B +68 B
WebGPU Nodes	547.93 150.06	548.13 150.12	+194 B +66 B