Auto merge of #20884 - jdm:more-limits, r=avadacatavra

Don't forward GL parameter gets for constant limits.

This avoids IPC traffic for unchanging constants that are determined when the GL context is created. These changes require https://github.com/emilio/rust-offscreen-rendering-context/pull/123.

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- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] These changes fix #20876.
- [x] There are tests for these changes

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components/canvas_traits/webgl.rs

@@ -480,16 +480,6 @@ parameters! {
             FrontFace = gl::FRONT_FACE,
             GenerateMipmapHint = gl::GENERATE_MIPMAP_HINT,
             GreenBits = gl::GREEN_BITS,
-            MaxCombinedTextureImageUnits = gl::MAX_COMBINED_TEXTURE_IMAGE_UNITS,
-            MaxCubeMapTextureSize = gl::MAX_CUBE_MAP_TEXTURE_SIZE,
-            MaxFragmentUniformVectors = gl::MAX_FRAGMENT_UNIFORM_VECTORS,
-            MaxRenderbufferSize = gl::MAX_RENDERBUFFER_SIZE,
-            MaxTextureImageUnits = gl::MAX_TEXTURE_IMAGE_UNITS,
-            MaxTextureSize = gl::MAX_TEXTURE_SIZE,
-            MaxVaryingVectors = gl::MAX_VARYING_VECTORS,
-            MaxVertexAttribs = gl::MAX_VERTEX_ATTRIBS,
-            MaxVertexTextureImageUnits = gl::MAX_VERTEX_TEXTURE_IMAGE_UNITS,
-            MaxVertexUniformVectors = gl::MAX_VERTEX_UNIFORM_VECTORS,
             PackAlignment = gl::PACK_ALIGNMENT,
             RedBits = gl::RED_BITS,
             SampleBuffers = gl::SAMPLE_BUFFERS,