fix(ci): add the missing dollar sign

Signed-off-by: Jiaxiao (mossaka) Zhou <[email protected]>

Author: Mossaka

.github/workflows/action-build.yaml

@@ -23,7 +23,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions-rust-lang/setup-rust-toolchain@v1
         with:
-          cache-key: rust-cache-${{ matrix.config.os }}-{{ matrix.config.arch}}
+          cache-key: rust-cache-${{ matrix.config.os }}-${{ matrix.config.arch}}
       - name: Setup build env
         run: |
           make setup