devDeps: add depcheck, lint:dependencies packages script

.depcheckrc.json

@@ -0,0 +1,11 @@
+{
+  "ignores": [
+    "@lavamoat/allow-scripts",
+    "@lavamoat/preinstall-always-fail",
+    "@metamask/auto-changelog",
+    "@types/*",
+    "prettier-plugin-packagejson",
+    "ts-node",
+    "typedoc"
+  ]
+}

package.json

@@ -27,9 +27,10 @@
     "build": "tsc --project tsconfig.build.json",
     "build:clean": "rimraf dist && yarn build",
     "build:docs": "typedoc",
-    "lint": "yarn lint:eslint && yarn lint:misc --check",
+    "lint": "yarn lint:eslint && yarn lint:misc --check && yarn lint:dependencies --check",
+    "lint:dependencies": "depcheck && yarn dedupe",
     "lint:eslint": "eslint . --cache --ext js,ts",
-    "lint:fix": "yarn lint:eslint --fix && yarn lint:misc --write",
+    "lint:fix": "yarn lint:eslint --fix && yarn lint:misc --write && yarn lint:dependencies",
     "lint:misc": "prettier '**/*.json' '**/*.md' '!CHANGELOG.md' '**/*.yml' '!.yarnrc.yml' --ignore-path .gitignore --no-error-on-unmatched-pattern",
     "prepack": "./scripts/prepack.sh",
     "test": "jest && jest-it-up",
@@ -49,6 +50,7 @@
     "@types/jest": "^28.1.6",
     "@typescript-eslint/eslint-plugin": "^5.42.1",
     "@typescript-eslint/parser": "^5.42.1",
+    "depcheck": "^1.4.5",
     "eslint": "^8.27.0",
     "eslint-config-prettier": "^8.5.0",
     "eslint-plugin-import": "^2.26.0",