Update dependency @types/jest to v26.0.8

Author: renovate-bot

package-lock.json

@@ -33,7 +33,7 @@
     "picomatch": "2.2.2"
   },
   "devDependencies": {
-    "@types/jest": "26.0.3",
+    "@types/jest": "26.0.8",
     "@types/node": "13.13.12",
     "@types/picomatch": "2.2.1",
     "@typescript-eslint/eslint-plugin": "3.4.0",