Update jest monorepo to v26

Author: renovate-bot

package.json

@@ -48,7 +48,7 @@
     "@babel/preset-react": "7.12.10",
     "babel-core": "7.0.0-bridge.0",
     "babel-eslint": "10.1.0",
-    "babel-jest": "23.6.0",
+    "babel-jest": "26.6.3",
     "babel-loader": "8.2.2",
     "babel-plugin-version-inline": "1.0.0",
     "codemirror": "5.59.1",
@@ -59,7 +59,7 @@
     "file-loader": "6.0.0",
     "html-webpack-plugin": "4.5.0",
     "image-webpack-loader": "6.0.0",
-    "jest": "25.5.4",
+    "jest": "26.6.3",
     "json-loader": "0.5.7",
     "markdown-it-anchor": "5.3.0",
     "markdown-it-table-of-contents": "0.4.4",