CI: cache build artifacts + --locked build (speeds the aarch64 host build)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GLUwWE2KmFPzhKaf67tWbx

.gitea/workflows/release.yml

@@ -30,11 +30,18 @@ jobs:
         with:
           targets: ${{ matrix.target }}
 
-      - name: Cache cargo registry
+      - name: Cache cargo + build artifacts
         uses: actions/cache@v3
         with:
-          path: ~/.cargo/registry
+          path: |
+            ~/.cargo/registry
+            ~/.cargo/git
+            target
           key: ${{ runner.os }}-${{ matrix.arch }}-cargo-${{ hashFiles('Cargo.lock') }}
+          # Reuse a prior build's compiled deps (pipewire-sys/bindgen is slow,
+          # especially on the aarch64 host) even when Cargo.lock changed.
+          restore-keys: |
+            ${{ runner.os }}-${{ matrix.arch }}-cargo-
 
       - name: Ensure audio build deps (libpipewire + clang for native capture)
         run: |
@@ -56,7 +63,7 @@ jobs:
           fi
 
       - name: Build
-        run: cargo build --release --target ${{ matrix.target }}
+        run: cargo build --release --locked --target ${{ matrix.target }}
 
       - name: Package
         run: |