fix: package.json to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JS-BRACES-6838727
- https://snyk.io/vuln/SNYK-JS-MICROMATCH-6838728

package.json

@@ -126,7 +126,7 @@
         "karma-firefox-launcher": "^1.3.0",
         "karma-mocha": "^2.0.1",
         "karma-spec-reporter": "0.0.32",
-        "lerna": "^4.0.0",
+        "lerna": "^6.5.0",
         "mocha": "^6.2.3",
         "nyc": "^14.1.1",
         "pify": "^4.0.1",
@@ -135,7 +135,7 @@
         "ts-node": "^9.0.0",
         "typescript": "^3.9.7",
         "wait-port": "^0.2.9",
-        "webpack": "^4.44.2",
+        "webpack": "^5.0.0",
         "webpack-cli": "^4.9.1"
     }
 }