[6.8] Upgrade Karma and friends (#88472)

Co-authored-by: Kibana Machine <42973632+kibanamachine@users.noreply.github.com>

package.json

@@ -395,13 +395,13 @@
     "jest-raw-loader": "^1.0.1",
     "jimp": "0.2.28",
     "json5": "^1.0.1",
-    "karma": "3.1.4",
-    "karma-chrome-launcher": "2.1.1",
-    "karma-coverage": "1.1.1",
-    "karma-firefox-launcher": "1.0.1",
+    "karma": "6.0.0",
+    "karma-chrome-launcher": "2.2.0",
+    "karma-coverage": "1.1.2",
+    "karma-firefox-launcher": "1.1.0",
     "karma-ie-launcher": "1.0.0",
     "karma-junit-reporter": "1.2.0",
-    "karma-mocha": "1.3.0",
+    "karma-mocha": "2.0.0",
     "karma-safari-launcher": "1.0.0",
     "leadfoot": "1.7.6",
     "license-checker": "^16.0.0",