chore: bump karma-firefox-launcher from 1.3.0 to 2.1.1 (#327)

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

package-lock.json

@@ -48,7 +48,7 @@
     "karma-chrome-launcher": "^3.0.0",
     "karma-cli": "^2.0.0",
     "karma-coverage-istanbul-reporter": "^3.0.3",
-    "karma-firefox-launcher": "^1.3.0",
+    "karma-firefox-launcher": "^2.1.1",
     "karma-mocha": "^2.0.0",
     "karma-sinon-chai": "^2.0.2",
     "karma-sourcemap-loader": "^0.3.7",