fix: incorrect version of @types/jest

Author: sinedied

generators/app/templates/_package.json

@@ -138,7 +138,7 @@
     "@types/jasmine": "^3.5.14",
     "@types/jasminewd2": "^2.0.8",
 <% if (props.tools.includes('jest')) { -%>
-    "@types/jest": "^26.4.2",
+    "@types/jest": "^26.0.12",
 <% } -%>
     "@types/node": "^12.12.54",
 <% if (props.utility.includes('lodash')) { -%>