Tweak docs to no longer ask for manual installation of cargo vet.

I tested that after https://crrev.com/c/5366668 landed
`//tools/crates/run_cargo_vet.py` works (using
`//third_party/rust-toolchain/bin/cargo-vet`) without requiring an
explicit installation step (I've verified that `locate` doesn't find any
other `cargo-vet` binaries on my machine).

Based on the above, this CL removes docs that ask for a separate
installation step for `cargo vet`.

Bug: 326234536
Change-Id: I8015fe700c5cc477d340e9205031b0bd533c1e10
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5387733
Commit-Queue: Łukasz Anforowicz <lukasza@chromium.org>
Reviewed-by: danakj <danakj@chromium.org>
Auto-Submit: Łukasz Anforowicz <lukasza@chromium.org>
Commit-Queue: danakj <danakj@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1276978}

docs/rust-unsafe.md

@@ -54,11 +54,6 @@ Additional notes:
   (e.g. Android, Fuchsia, etc.).  This means that adding a new crate does not
   necessarily require a new audit if the crate has already been audited by
   other projects.
-* Before using `tools/crates/run_cargo_vet.py` you may need to install the tool
-  by running:
-  `tools/crates/run_cargo.py install cargo-vet --locked --version=0.9.1`
-    - TODO(https://crbug.com/326234536): Prebuild `cargo-vet` and distribute
-      via/into `third_party/rust-toolchain` (i.e. together with `rustc`).
 * For now we kindly ask you that audit updates in `audits.toml`
   should be part of the submitted CL so that `run_cargo_vet.py check` will
   continue to pass after the CL lands.

docs/rust.md

@@ -80,10 +80,6 @@ To use a third-party crate "bar" version 3 from first party code:
 1. Verify if all new dependencies are already audited by running `cargo vet`
    See [`rust-unsafe.md#cargo-vet-policy`](rust-unsafe.md#cargo-vet-policy) for
    more details.  This boils down to:
-   * Install `cargo vet` if it's not yet installed:
-      * `tools/crates/run_cargo.py install cargo-vet --locked --version=0.9.1`
-      * TODO: Pre-package `cargo-vet` into `rust-toolchain`:
-        https://crrev.com/c/5366668
    * `./tools/crates/run_cargo_vet.py check`
    * If `check` fails, then there are missing audits, which need to be added to
      `//third_party/rust/chromium_crates_io/supply-chain/audits.toml`.

tools/crates/create_update_cl.md

@@ -77,10 +77,6 @@ closest to `origin/main`):
       that the automated script has listed in the CL description (e.g. if some
       of the criteria are already covered by `audits.toml` imported from other
       projects).
-    - Install `cargo vet` if it's not yet installed:
-        * `tools/crates/run_cargo.py install cargo-vet --locked --version=0.9.1`
-        * TODO: Pre-package `cargo-vet` into `rust-toolchain`:
-          https://crrev.com/c/5366668
 1. Follow the cargo vet instructions to inspect diffs and certify the results
 1. `git add third_party/rust/chromium_crates_io/supply-chain`.
    `git commit -m 'cargo vet'`