OpenXR: Do not use SRGB swapchains with OpenGL

This commit removes SRGB swapchain options for use with OpenGL, to avoid
the hardware doing an additional SRGB conversion and thus causing colors
to differ from other rendering paths.

modules/openxr/extensions/openxr_opengl_extension.cpp

@@ -157,7 +157,6 @@ void *OpenXROpenGLExtension::set_session_create_and_get_next_pointer(void *p_nex
 }
 
 void OpenXROpenGLExtension::get_usable_swapchain_formats(Vector<int64_t> &p_usable_swap_chains) {
-	p_usable_swap_chains.push_back(GL_SRGB8_ALPHA8);
 	p_usable_swap_chains.push_back(GL_RGBA8);
 }