Update dependency @webcomponents/webcomponentsjs to ^2.8.0

Author: renovate[bot]

package-lock.json

@@ -47,7 +47,7 @@
     "@babel/preset-env": "7.22.9",
     "@open-wc/testing-helpers": "^2.3.0",
     "@types/jest": "29.5.6",
-    "@webcomponents/webcomponentsjs": "^2.6.0",
+    "@webcomponents/webcomponentsjs": "^2.8.0",
     "babel-loader": "9.1.3",
     "codecov": "^3.8.3",
     "concurrently": "7.6.0",