Rename env var and tweak hashing to align with cargo leptos #1789

Job	Run time
get-leptos-changed / Detect Source Change	5s
CI (integrations/axum) / Run ci (nightly-2024-01-29)	11m 51s
CI (integrations/actix) / Run ci (nightly-2024-01-29)	11m 24s
CI (leptos) / Run ci (nightly-2024-01-29)	39m 3s
CI (integrations/utils) / Run ci (nightly-2024-01-29)	11m 0s
CI (leptos_config) / Run ci (nightly-2024-01-29)	10m 23s
CI (leptos_dom) / Run ci (nightly-2024-01-29)	17m 26s
CI (leptos_hot_reload) / Run ci (nightly-2024-01-29)	10m 25s
CI (leptos_macro) / Run ci (nightly-2024-01-29)	23m 7s
CI (leptos_reactive) / Run ci (nightly-2024-01-29)	38m 13s
CI (leptos_server) / Run ci (nightly-2024-01-29)	17m 23s
CI (meta) / Run ci (nightly-2024-01-29)	10m 53s
CI (router) / Run ci (nightly-2024-01-29)	12m 33s
CI (server_fn) / Run ci (nightly-2024-01-29)	18m 9s
CI (server_fn_macro) / Run ci (nightly-2024-01-29)	11m 51s
CI (server_fn/server_fn_macro_default) / Run ci (nightly-2024-01-29)	10m 23s
	4h 14m 9s

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