Bump dtolnay/rust-toolchain

Bumps the github_actions group with 1 update in the / directory: [dtolnay/rust-toolchain](https://github.com/dtolnay/rust-toolchain).


Updates `dtolnay/rust-toolchain` from 1.70 to 1.90
- [Release notes](https://github.com/dtolnay/rust-toolchain/releases)
- [Commits](dtolnay/rust-toolchain@1.70...1.90)

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

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

.github/workflows/tests.yml

@@ -24,7 +24,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - name: Install Rust toolchain
-        uses: dtolnay/rust-toolchain@1.70
+        uses: dtolnay/rust-toolchain@1.90
         if: matrix.python-version == '3.10'
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v5