build(deps-dev): Bump ts-jest from 26.5.5 to 26.5.6

Bumps [ts-jest](https://github.com/kulshekhar/ts-jest) from 26.5.5 to 26.5.6.
- [Release notes](https://github.com/kulshekhar/ts-jest/releases)
- [Changelog](https://github.com/kulshekhar/ts-jest/blob/master/CHANGELOG.md)
- [Commits](kulshekhar/ts-jest@v26.5.5...v26.5.6)

Signed-off-by: dependabot[bot] <support@github.com>

package.json

@@ -50,7 +50,7 @@
         "htmlparser2": "^6.1.0",
         "jest": "^26.6.3",
         "prettier": "^2.3.0",
-        "ts-jest": "^26.5.5",
+        "ts-jest": "^26.5.6",
         "typescript": "^4.2.4"
     },
     "jest": {