fix: install rust via rustup in workflow

.gitea/workflows/rust-cache-test.yml

@@ -17,12 +17,16 @@ jobs:
       - name: Checkout code
         uses: https://gitea.com/actions/checkout@v4
 
+      - name: Install Rust
+        run: |
+          curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y --default-toolchain stable
+          source "$HOME/.cargo/env"
+
       - name: Get Cargo lock hash
         id: hash
         run: |
+          source "$HOME/.cargo/env"
           echo "hash=$(cat Cargo.lock Cargo.toml | sha256sum | cut -d' ' -f1)" >> $GITHUB_OUTPUT
-          echo "=== Manifest hash ==="
-          echo "${{ env.hash }}"
 
       - name: Cache cargo
         uses: https://gitea.com/actions/cache@v3
@@ -37,21 +41,26 @@ jobs:
 
       - name: Show cache info (before build)
         run: |
+          source "$HOME/.cargo/env"
           echo "=== Cache Key ==="
           echo "rust-${{ runner.os }}-${{ steps.hash.outputs.hash }}"
           echo ""
           echo "=== Cargo cache directories (before build) ==="
           du -sh ~/.cargo/registry ~/.cargo/git target 2>/dev/null || echo "Dirs not yet present"
           echo ""
-          echo "=== Cargo version ==="
+          echo "=== Cargo/Rust versions ==="
           cargo --version
           rustc --version
 
       - name: Build
-        run: cargo build --verbose
+        run: |
+          source "$HOME/.cargo/env"
+          cargo build --verbose
 
       - name: Run
-        run: cargo run
+        run: |
+          source "$HOME/.cargo/env"
+          cargo run
 
       - name: Check cache after build
         run: |