ci: try caching

.forgejo/workflows/build.yaml

@@ -1,12 +1,25 @@
 on: [push]
 jobs:
   build:
-    container:
-      image: alpine:edge
+    container: { image: "alpine:edge" }
     steps:
-      - run: apk update
-      - run: apk add tree rustup git just cloc build-base clang20-dev pipewire-jack-dev lilv-dev serd-dev
-      - run: git clone --recursive $GITHUB_SERVER_URL/$GITHUB_REPOSITORY .
+
+      - name: install deps
+        run:  apk add --no-cache nodejs tree rustup git just cloc build-base clang20-dev pipewire-jack-dev lilv-dev serd-dev
+
+      - id:   cache
+        name: cache restore
+        uses: https://data.forgejo.org/actions/cache/restore@v4
+        with:
+          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
+          path: |
+            ~/.cargo/bin/
+            ~/.cargo/registry/index/
+            ~/.cargo/registry/cache/
+            ~/.cargo/git/db/
+            target/
+
+      - run: git clone --depth 1 --recursive $GITHUB_SERVER_URL/$GITHUB_REPOSITORY .
       - run: whoami && pwd && tree
       - run: cloc src/ && cloc .
       - run: rustup-init -y
@@ -15,3 +28,14 @@ jobs:
       - run: source "$HOME/.cargo/env" && RUSTFLAGS="-Ctarget-feature=-crt-static" just test
       - run: source "$HOME/.cargo/env" && RUSTFLAGS="-Ctarget-feature=-crt-static" just build-release
       - run: tree
+
+      - name: cache save
+        uses: https://data.forgejo.org/actions/cache/save@v4
+        with:
+          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
+          path: |
+            ~/.cargo/bin/
+            ~/.cargo/registry/index/
+            ~/.cargo/registry/cache/
+            ~/.cargo/git/db/
+            target/