Update dependency ts-jest to v26.5.6

Author: renovate-bot

repos/redux-toolkit/package-lock.json

@@ -75,7 +75,7 @@
     "size-limit": "4.11.0",
     "source-map": "0.7.3",
     "terser": "5.6.1",
-    "ts-jest": "26.5.5",
+    "ts-jest": "26.5.6",
     "tslib": "1.14.1",
     "typescript": "4.2.3",
     "yargs": "15.4.1"