ci: bump dtolnay/rust-toolchain from 1.84.0 to 1.100.0

Bumps [dtolnay/rust-toolchain](https://github.com/dtolnay/rust-toolchain) from 1.84.0 to 1.100.0.
- [Release notes](https://github.com/dtolnay/rust-toolchain/releases)
- [Commits](dtolnay/rust-toolchain@1.84.0...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] <[email protected]>

Author: dependabot[bot]

.github/workflows/rust.yml

@@ -29,7 +29,7 @@ jobs:
       - name: Install dependencies (macOS)
         if: runner.os == 'Macos'
         run: brew install protobuf fish shellcheck
-      - uses: dtolnay/rust-toolchain@1.84.0
+      - uses: dtolnay/rust-toolchain@1.100.0
         id: toolchain
         with:
           components: clippy
@@ -96,7 +96,7 @@ jobs:
     timeout-minutes: 60
     steps:
       - uses: actions/checkout@v4
-      - uses: dtolnay/rust-toolchain@1.84.0
+      - uses: dtolnay/rust-toolchain@1.100.0
         id: toolchain
         with:
           components: clippy