More inline with bevy's builds.

.github/workflows/rust.yml

@@ -18,6 +18,16 @@ jobs:
     runs-on: ${{ matrix.os }}
 
     steps:
+    - uses: actions/checkout@v3
+    - uses: actions/cache@v3
+      with:
+        path: |
+          ~/.cargo/bin/
+          ~/.cargo/registry/index/
+          ~/.cargo/registry/cache/
+          ~/.cargo/git/db/
+          target/
+        key: ${{ runner.os }}-cargo-build-stable-${{ hashFiles('**/Cargo.toml') }}
     - name: Install alsa and udev
       run: sudo apt-get update; sudo apt-get install --no-install-recommends libasound2-dev libudev-dev
       if: runner.os == 'linux'