### Godot version

4.1.1.stable, 4.2.dev (2282fc5de)

### System information

Arch Linux - X11 - GLES3 (Compatibility) - NVIDIA GeForce RTX 3060 Ti (nvidia; 535.104.05) - 13th Gen Intel(R) Core(TM) i5-13400F (16 Threads)

### Issue description

When using Compatibility renderer, adjusting the Alpha component of clear color affects 2D editor content.

This does not happen when using Forward+ or Mobile renderer. Does not affect 3D editor and the running game.


https://github.com/godotengine/godot/assets/372476/e398522e-590a-4832-959f-ea8ba8e71c5d



### Steps to reproduce

1. Create a project using Compatibility renderer.
2. Adjust the clear color's alpha component in Project Settings.

### Minimal reproduction project

N/A
material_storage->shader_initialize(default_clip_children_shader);
		material_storage->shader_set_code(default_clip_children_shader, R"(
// Default clip children shader.
shader_type canvas_item;
render_mode unshaded;
uniform sampler2D screen_texture : hint_screen_texture, repeat_disable, filter_nearest;
void fragment() {
	vec4 c = textureLod(screen_texture, SCREEN_UV, 0.0);
	COLOR.rgb = c.rgb;
}
)");
		default_clip_children_material = material_storage->material_allocate();
		material_storage->material_initialize(default_clip_children_material);
		material_storage->material_set_shader(default_clip_children_material, default_clip_children_shader);
	}
	default_canvas_texture = texture_storage->canvas_texture_allocate();
	texture_storage->canvas_texture_initialize(default_canvas_texture);
	state.time = 0.0;
}
RasterizerCanvasGLES3::~RasterizerCanvasGLES3() {
	singleton = nullptr;
	GLES3::MaterialStorage *material_storage = GLES3::MaterialStorage::get_singleton();
	material_storage->shaders.canvas_shader.version_free(data.canvas_shader_default_version);
	shadow_render.shader.version_free(shadow_render.shader_version);
	material_storage->material_free(default_canvas_group_material);
	material_storage->shader_free(default_canvas_group_shader);
	material_storage->material_free(default_clip_children_material);
	material_storage->shader_free(default_clip_children_shader);
	singleton = nullptr;
	glDeleteBuffers(1, &data.canvas_quad_vertices);