add rust build cache on ci

.forgejo/workflows/build.yaml

@@ -11,6 +11,15 @@ jobs:
       - uses: actions/checkout@v3
         name: Checkout
       - uses: https://github.com/DeterminateSystems/magic-nix-cache-action@main
+      - uses: actions/cache@v3
+        with:
+          path: |
+            ~/.cargo/bin/
+            ~/.cargo/registry/index/
+            ~/.cargo/registry/cache/
+            ~/.cargo/git/db/
+            target/      
+          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
       - name: Run tests
         run: |
           nix develop -c cargo nextest run --run-ignored all
@@ -23,6 +32,15 @@ jobs:
       - uses: actions/checkout@v3
         name: Checkout
       - uses: https://github.com/DeterminateSystems/magic-nix-cache-action@main
+      - uses: actions/cache@v3
+        with:
+          path: |
+            ~/.cargo/bin/
+            ~/.cargo/registry/index/
+            ~/.cargo/registry/cache/
+            ~/.cargo/git/db/
+            target/      
+          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
       - name: 
         run: |
           nix build
@@ -35,6 +53,15 @@ jobs:
         run: |
           nix flake metadata
       - uses: https://github.com/DeterminateSystems/magic-nix-cache-action@main
+      - uses: actions/cache@v3
+        with:
+          path: |
+            ~/.cargo/bin/
+            ~/.cargo/registry/index/
+            ~/.cargo/registry/cache/
+            ~/.cargo/git/db/
+            target/      
+          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
       - name: Statix
         run: |
           nix develop -c statix check