Enable const generics component tests for yew-functional-macro

[lukechu10]

yew/packages/yew-functional-macro/tests/function_attr/generic-pass.rs

Lines 23 to 31 in 8d96a44

	// TODO: uncomment when min_const_generics are in stable and Rust version in CI is bumped
	// #[::yew_functional::function_component(ConstGenerics)]
	// fn const_generics<const N: i32>() -> ::yew::Html {
	// ::yew::html! {
	// <div>
	// { N }
	// </div>
	// }
	// }

Originally posted by @siku2 in #1756 (comment)

[siku2]

Just as a note: Once it lands, we can easily bump the Rust version used for tests to 1.51 without having to change the MSRV.