Cache Rust deps in GHA

Author: penelopeysm

.github/workflows/deploy.yaml

@@ -21,6 +21,11 @@ jobs:
       - name: Set up Rust
         uses: actions-rust-lang/setup-rust-toolchain@v1
 
+      - name: Cache Rust dependencies
+        uses: Swatinem/rust-cache@v2
+        with:
+          workspaces: "rust"
+
       - name: Generate JSON containing all concerts
         working-directory: rust
         run: cargo run