Bump ts-jest from 25.5.1 to 26.5.4

Bumps [ts-jest](https://github.com/kulshekhar/ts-jest) from 25.5.1 to 26.5.4.
- [Release notes](https://github.com/kulshekhar/ts-jest/releases)
- [Changelog](https://github.com/kulshekhar/ts-jest/blob/master/CHANGELOG.md)
- [Commits](kulshekhar/ts-jest@v25.5.1...v26.5.4)

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

package-lock.json

@@ -46,7 +46,7 @@
     "@zeit/ncc": "^0.22.3",
     "jest": "^26.6.3",
     "prettier": "^2.2.1",
-    "ts-jest": "^25.5.1",
+    "ts-jest": "^26.5.4",
     "typescript": "^3.9.7"
   }
 }