Update dependency ts-jest to v26.5.6

Author: renovate-bot

package-lock.json

@@ -20,7 +20,7 @@
     "lint-staged": "10.5.4",
     "prettier": "2.2.1",
     "rimraf": "3.0.2",
-    "ts-jest": "26.5.5",
+    "ts-jest": "26.5.6",
     "ts-node": "9.1.1",
     "typescript": "4.2.4"
   },