chore: Add cargo-machete to detect unused dependencies (#817)

Author: tottoto

.github/workflows/continuous-integration-workflow.yaml

@@ -50,6 +50,22 @@ jobs:
 #           args: --workspace --all-targets
 #           toolchain: stable
 
+  machete:
+    runs-on: ubuntu-latest
+    steps:
+      - name: checkout
+        uses: actions/checkout@v3
+        with:
+          submodules: recursive
+      - name: install toolchain
+        uses: dtolnay/rust-toolchain@stable
+      - name: Install cargo-machete
+        uses: baptiste0928/cargo-install@v1
+        with:
+          crate: cargo-machete
+      - name: Check unused dependencies
+        run: cargo machete
+
   test:
     runs-on: ${{ matrix.os }}
     strategy:

conformance/Cargo.toml

@@ -11,7 +11,6 @@ edition = "2018"
 [dependencies]
 bytes = "1"
 env_logger = { version = "0.8", default-features = false }
-log = "0.4"
 prost = { path = ".." }
 protobuf = { path = "../protobuf" }
 tests = { path = "../tests" }

prost-types/Cargo.toml

@@ -22,7 +22,6 @@ default = ["std"]
 std = ["prost/std"]
 
 [dependencies]
-bytes = { version = "1", default-features = false }
 prost = { version = "0.11.6", path = "..", default-features = false, features = ["prost-derive"] }
 
 [dev-dependencies]

protobuf/Cargo.toml

@@ -9,7 +9,6 @@ publish = false
 edition = "2018"
 
 [dependencies]
-bytes = { version = "1", default-features = false }
 prost = { path = ".." }
 prost-types = { path = "../prost-types" }
 
@@ -39,3 +38,6 @@ bench = false
 [[bench]]
 name = "dataset"
 harness = false
+
+[package.metadata.cargo-machete]
+ignored = ["prost-types"]