recommend rustup check vs specific version

Signed-off-by: Neal McBurnett <nealmcb@gmail.com>

Author: nealmcb

docs/content/rust-components.md

@@ -282,7 +282,7 @@ Sometimes things can go wrong, especially such early projects. If you bump into
 issues building and running your Rust component:
 
 - ensure `cargo` is present in your path
-- ensure your [Rust](https://www.rust-lang.org/) version is recent, at [1.56+](https://www.rust-lang.org/tools/install)
+- ensure your [Rust](https://www.rust-lang.org/) version is recent, via `rustup check`
 - ensure `wasm32-wasi` target is configured for your Rust installation —
 you can add it by running `rustup target add wasm32-wasi`
 - build a `release` version of the component — all Spin application definitions