Roll libc: 0.2.159 => 0.2.161 in //third_party/rust.

This CL has been created semi-automatically.  The expected review
process and other details can be found at
//tools/crates/create_update_cl.md

Updated crates:

* libc: 0.2.159 => 0.2.161

Chromium `supply-chain/config.toml` policy requires that the following
audit criteria are met (note that these are the *minimum* required
criteria and `supply-chain/audits.toml` can and should record a stricter
certification if possible;  see also //docs/rust-unsafe.md):

* libc@0.2.161: crypto-safe, safe-to-deploy, ub-risk-2

Bug: None
Change-Id: I2e2c61572c99844279e6b13eb215e1055cf5a1a1
Cq-Include-Trybots: chromium/try:android-rust-arm32-rel
Cq-Include-Trybots: chromium/try:android-rust-arm64-dbg
Cq-Include-Trybots: chromium/try:android-rust-arm64-rel
Cq-Include-Trybots: chromium/try:linux-rust-x64-dbg
Cq-Include-Trybots: chromium/try:linux-rust-x64-rel
Cq-Include-Trybots: chromium/try:win-rust-x64-dbg
Cq-Include-Trybots: chromium/try:win-rust-x64-rel
Disable-Rts: True
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5962520
Reviewed-by: danakj <danakj@chromium.org>
Commit-Queue: Liza Burakova <liza@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1373637}