### 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
CanvasShaderGLES3::ShaderVariant variant = state.canvas_instance_batches[i].shader_variant;
		uint64_t specialization = 0;
		specialization |= uint64_t(state.canvas_instance_batches[i].lights_disabled);
		specialization |= uint64_t(!GLES3::Config::get_singleton()->float_texture_supported) << 1;
		RID shader_version = data.canvas_shader_default_version;
		if (material_data) {
			if (material_data->shader_data->version.is_valid() && material_data->shader_data->valid) {
				
				material_data->bind_uniforms();
				shader_version = material_data->shader_data->version;
			}
		}
		bool success = GLES3::MaterialStorage::get_singleton()->shaders.canvas_shader.version_bind_shader(shader_version, variant, specialization);
		if (!success) {
			continue;
		}
		GLES3::CanvasShaderData::BlendMode blend_mode = state.canvas_instance_batches[i].blend_mode;
		Color blend_color = state.canvas_instance_batches[i].blend_color;
		if (last_blend_mode != blend_mode || last_blend_color != blend_color) {
			if (last_blend_mode == GLES3::CanvasShaderData::BLEND_MODE_DISABLED) {
				
				glEnable(GL_BLEND);
			} else if (blend_mode == GLES3::CanvasShaderData::BLEND_MODE_DISABLED) {
				
				glDisable(GL_BLEND);
			}
			switch (blend_mode) {
				case GLES3::CanvasShaderData::BLEND_MODE_DISABLED: {
					
				} break;