chore(deps): update dependency karma to v6

Author: renovate-bot

package.json

@@ -58,7 +58,7 @@
     "esm": "^3.2.25",
     "husky": "^4.3.5",
     "istanbul-instrumenter-loader": "^3.0.1",
-    "karma": "^5.2.3",
+    "karma": "^6.1.0",
     "karma-chai": "^0.1.0",
     "karma-chrome-launcher": "^3.1.0",
     "karma-coverage-istanbul-reporter": "^3.0.3",