Add a cargo machete CI step (#5171)

`cargo machete` looks for unused dependencies

.github/workflows/cargo_machete.yml

@@ -0,0 +1,12 @@
+name: Cargo Machete
+
+on: [push, pull_request]
+
+jobs:
+  cargo-machete:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+      - name: Machete
+        uses: bnjbvr/cargo-machete@main