ci: bump dtolnay/rust-toolchain from 1.85.0 to 1.100.0

Bumps [dtolnay/rust-toolchain](https://github.com/dtolnay/rust-toolchain) from 1.85.0 to 1.100.0.
- [Release notes](https://github.com/dtolnay/rust-toolchain/releases)
- [Commits](dtolnay/rust-toolchain@1.85.0...1.100.0)

---
updated-dependencies:
- dependency-name: dtolnay/rust-toolchain
  dependency-version: 1.100.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -121,7 +121,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v6
-      - uses: dtolnay/rust-toolchain@1.85.0  # MSRV for Rust 2024 edition
+      - uses: dtolnay/rust-toolchain@1.100.0  # MSRV for Rust 2024 edition
       - uses: Swatinem/rust-cache@v2
       - name: Check MSRV
         run: cargo check --all-features