CI: Add bitrot check to ensure examples and benchmarks still compile

.github/workflows/ci.yml

@@ -80,6 +80,24 @@ jobs:
         working-directory: ./age
         run: cargo build --verbose --no-default-features --target ${{ matrix.target }}
 
+  bitrot:
+    name: Bitrot
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions-rs/toolchain@v1
+        with:
+          toolchain: 1.51.0
+          override: true
+      - name: Install linux build dependencies
+        run: sudo apt install libfuse-dev
+      - name: cargo check
+        uses: actions-rs/cargo@v1
+        with:
+          command: check
+          args: --tests --examples --benches --all-features
+
   codecov:
     name: Code coverage
     runs-on: ubuntu-latest