build(deps): bump dtolnay/rust-toolchain in /.github/workflows

Bumps [dtolnay/rust-toolchain](https://github.com/dtolnay/rust-toolchain) from 1.64.0 to 1.80.0.
- [Release notes](https://github.com/dtolnay/rust-toolchain/releases)
- [Commits](dtolnay/rust-toolchain@1.64.0...1.80.0)

---
updated-dependencies:
- dependency-name: dtolnay/rust-toolchain
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/rust.yml

@@ -28,7 +28,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v1
-      - uses: dtolnay/rust-toolchain@1.70.0
+      - uses: dtolnay/rust-toolchain@1.80.0
         with:
           target: aarch64-linux-android
       - name: Check