### Godot version

4.1.1 stable

### System information

Windows 10

### Issue description

this is the default size loaded on startup 1024 which seems fine but it actually have loaded the default [2048] and ignored the size in project settings
![image](https://github.com/godotengine/godot/assets/53877170/c8c71de7-468a-487f-8e6c-dba1ce0f8fa5)

changing it now to any size will break it 
[2048]
![image](https://github.com/godotengine/godot/assets/53877170/3082ff09-b7d7-41f7-8fbb-813074a54135)

[512]
![image](https://github.com/godotengine/godot/assets/53877170/5ea4620f-52b5-4d0e-a5f5-747e777cd59d)


### Steps to reproduce

change 2d shadow atlas size in project settings while using compatibility renderer. 

### Minimal reproduction project

_
const Color *color_ptr = p_colors.ptr();
			for (uint32_t i = 0; i < vertex_count; i++) {
				fptr[base_offset + i * stride + 0] = color_ptr[i].r;
				fptr[base_offset + i * stride + 1] = color_ptr[i].g;
				fptr[base_offset + i * stride + 2] = color_ptr[i].b;
				fptr[base_offset + i * stride + 3] = color_ptr[i].a;
			}
			base_offset += 4;
		} else {
			glDisableVertexAttribArray(RS::ARRAY_COLOR);
			pb.color_disabled = true;
			pb.color = p_colors.size() == 1 ? p_colors[0] : Color(1.0, 1.0, 1.0, 1.0);
		}
		if ((uint32_t)p_uvs.size() == vertex_count) {
			glEnableVertexAttribArray(RS::ARRAY_TEX_UV);
			glVertexAttribPointer(RS::ARRAY_TEX_UV, 2, GL_FLOAT, GL_FALSE, stride * sizeof(float), CAST_INT_TO_UCHAR_PTR(base_offset * sizeof(float)));
			const Vector2 *uv_ptr = p_uvs.ptr();
			for (uint32_t i = 0; i < vertex_count; i++) {
				fptr[base_offset + i * stride + 0] = uv_ptr[i].x;
				fptr[base_offset + i * stride + 1] = uv_ptr[i].y;
			}
			base_offset += 2;
		} else {
			glDisableVertexAttribArray(RS::ARRAY_TEX_UV);
		}
		if ((uint32_t)p_indices.size() == vertex_count * 4 && (uint32_t)p_weights.size() == vertex_count * 4) {
			glEnableVertexAttribArray(RS::ARRAY_BONES);
			glVertexAttribPointer(RS::ARRAY_BONES, 4, GL_UNSIGNED_INT, GL_FALSE, stride * sizeof(float), CAST_INT_TO_UCHAR_PTR(base_offset * sizeof(float)));
			const int *bone_ptr = p_bones.ptr();
			for (uint32_t i = 0; i < vertex_count; i++) {