fix: allow nested functions in `Attribute` (closes #2023) #1210

Job	Run time
get-leptos-changed / Detect Source Change	6s
CI (integrations/actix) / Run ci (nightly)	12m 36s
CI (integrations/axum) / Run ci (nightly)	19m 52s
CI (integrations/utils) / Run ci (nightly)	17m 5s
CI (integrations/viz) / Run ci (nightly)	12m 3s
CI (leptos) / Run ci (nightly)	1h 25m 9s
CI (leptos_config) / Run ci (nightly)	11m 15s
CI (leptos_dom) / Run ci (nightly)	18m 37s
CI (leptos_macro) / Run ci (nightly)	17m 35s
CI (leptos_hot_reload) / Run ci (nightly)	11m 3s
CI (leptos_reactive) / Run ci (nightly)	26m 56s
CI (leptos_server) / Run ci (nightly)	18m 39s
CI (meta) / Run ci (nightly)	12m 4s
CI (router) / Run ci (nightly)	13m 19s
CI (server_fn) / Run ci (nightly)	12m 0s
CI (server_fn_macro) / Run ci (nightly)	14m 16s
CI (server_fn/server_fn_macro_default) / Run ci (nightly)	11m 47s
	5h 14m 22s

Provide feedback