chore(deps): bump actions-rust-lang/setup-rust-toolchain

Bumps [actions-rust-lang/setup-rust-toolchain](https://github.com/actions-rust-lang/setup-rust-toolchain) from 1.10.1 to 1.12.0.
- [Release notes](https://github.com/actions-rust-lang/setup-rust-toolchain/releases)
- [Changelog](https://github.com/actions-rust-lang/setup-rust-toolchain/blob/main/CHANGELOG.md)
- [Commits](actions-rust-lang/setup-rust-toolchain@v1.10.1...v1.12.0)

---
updated-dependencies:
- dependency-name: actions-rust-lang/setup-rust-toolchain
  dependency-version: 1.12.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/library_rust_tests.yml

@@ -63,7 +63,7 @@ jobs:
           role-session-name: DDBEC-Dafny-Rust-Tests
 
       - name: Setup Rust Toolchain for GitHub CI
-        uses: actions-rust-lang/setup-rust-toolchain@v1.10.1
+        uses: actions-rust-lang/setup-rust-toolchain@v1.12.0
         with:
           components: rustfmt