Fix Zed release

[jnatherley]

/crates/gpui/src/element.rs:132:57
    |
132 |     fn render(&mut self, cx: &mut ViewContext<Self>) -> impl IntoElement;
    |                                                         ^^^^^^^^^^^^^^^^
    |

A number of errors when running cargo run dev, assuming because the zed package is pulled from GitHub master

[MatthiasGrandl]

No this is an unsupported rust version. There has been another issue with this same error.

[MatthiasGrandl]

See #2

[jnatherley]

I didn't check the Cargo.toml, cheers!