remove wasm file extension rename workaround

This modifies the webpack config instead of renaming the .wasm file
to workaround default webpack behavior regarding import .wasm files.

package.json

@@ -43,7 +43,6 @@
         "zen-push": "^0.2.1"
     },
     "scripts": {
-        "prepare": "mkdirp public/static/js && ncp node_modules/@pybricks/mpy-cross-v5/build/mpy-cross.wasm src/sagas/mpy-cross.emcwasm",
         "start": "craco start",
         "build": "craco build",
         "test": "craco test --env=./test/env.js",
@@ -76,8 +75,6 @@
         "eslint-plugin-prettier": "^3.3.1",
         "eslint-plugin-react": "^7.22.0",
         "jest-mock-extended": "^1.0.9",
-        "mkdirp": "^1.0.4",
-        "ncp": "^2.0.0",
         "prettier": "^2.2.1"
     }
 }