example suggestion: avoiding `{} <-` `|> await` boilerplate

We should make an example for this once we figure it out ourselves :p

Example of a problematic case:

{} <- log "Extracting current rust version from rust-toolchain.toml..." |> await
{ stable: currentStable, nightly: currentNightly } <- getCurrentVersionsFromToml |> await
{} <- log "Found versions:\n\t- stable: \(versionToStr currentStable)\n\t- nightly with date: \(dateToStr currentNightly)" |> await
# TODO Task.map to avoid repeated `{} <-`?
{} <- log "Searching for nightly matching stable-\(newRustVersion)..." |> await

newNightly <-
    findMatchingNigthly (versionFromStr newRustVersion) currentNightly
    |> await

{} <- log "New nightly: nightly-\(dateToStr newNightly)" |> await

TODO can we avoid boiler plate of `{} <-` and `await` here?
{} <-
    Path.fromStr "rust-toolchain.toml"
    |> updateToml newRustVersion
    |> await

{} <-
    Path.fromStr "examples/platform-switching/rust-platform/rust-toolchain.toml"
    |> updateToml newRustVersion
    |> await

{} <-
    Path.fromStr "Earthfile"
    |> updateEarthFile newRustVersion
    |> await

Start with the repeated pipeline snippets in the issue, including rust-toolchain.toml, examples/platform-switching/rust-platform/rust-toolchain.toml, and Earthfile. First determine whether the proposed boilerplate reduction is supported by the surrounding example code or requires an unresolved language change. Done means the intended approach is established and represented by a clear example covering the shown update and logging cases.