ci(fix): Install Rust toolchain for cargo-deny

Author: Techassi

.github/workflows/build.yml

@@ -60,6 +60,9 @@ jobs:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           persist-credentials: false
+      - uses: dtolnay/rust-toolchain@master
+        with:
+          toolchain: ${{ env.RUST_TOOLCHAIN_VERSION }}
       - uses: EmbarkStudios/cargo-deny-action@30f817c6f72275c6d54dc744fbca09ebc958599f # v2.0.12
         with:
           command: check ${{ matrix.checks }}