### Godot version

v4.1.dev.custom_build.a7276f1ce

### System information

Win10, AMD 2600, GeForce GTX 1060, Vulkan API 1.3.205

### Issue description

I can't get correct color data from an array of source_color type.
The color data is saved as **Color** in the file:
`shader_parameter/palette = [Color (1, 0, 0, 1), Color (0, 1, 0, 1), Color (0, 0, 1, 1)]`
Shouldn't it be saved as PackedColorArray?


### Steps to reproduce

1.Declare an array of source_color type.
2.Set colors.

### Minimal reproduction project

[shadertest.zip](https://github.com/godotengine/godot/files/11246504/shadertest.zip)

if (next_token.type == TK_BRACKET_OPEN) {
							_get_token(); 
							_get_token(); 
							next_token = _get_token();
						}
						_set_tkpos(prev_pos);
						ShaderNode::Varying &var = shader->varyings[identifier];
						String error;
						if (is_token_operator_assign(next_token.type)) {
							if (!_validate_varying_assign(shader->varyings[identifier], &error)) {
								_set_error(error);
								return nullptr;
							}
						} else {
							switch (var.stage) {
								case ShaderNode::Varying::STAGE_UNKNOWN: {
									if (var.type < TYPE_INT) {
										if (current_function == varying_function_names.vertex) {
											_set_error(vformat(RTR("Varying with '%s' data type may only be used in the 'fragment' function."), get_datatype_name(var.type)));
										} else {
											_set_error(vformat(RTR("Varying '%s' must be assigned in the 'fragment' function first."), identifier));
										}
										return nullptr;
									}
								} break;
								case ShaderNode::Varying::STAGE_VERTEX:
									if (current_function == varying_function_names.fragment || current_function == varying_function_names.light) {
										var.stage = ShaderNode::Varying::STAGE_VERTEX_TO_FRAGMENT_LIGHT;
									}