build(deps-dev): bump react-bootstrap from 2.6.0 to 2.7.4

Bumps [react-bootstrap](https://github.com/react-bootstrap/react-bootstrap) from 2.6.0 to 2.7.4.
- [Release notes](https://github.com/react-bootstrap/react-bootstrap/releases)
- [Changelog](https://github.com/react-bootstrap/react-bootstrap/blob/master/CHANGELOG.md)
- [Commits](react-bootstrap/react-bootstrap@v2.6.0...v2.7.4)

---
updated-dependencies:
- dependency-name: react-bootstrap
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

package.json

@@ -28,7 +28,7 @@
     "css-loader": "5.2.7",
     "file-loader": "6.2.0",
     "html-webpack-plugin": "4.5.2",
-    "react-bootstrap": "2.6.0",
+    "react-bootstrap": "2.7.4",
     "recursive-readdir": "2.2.3",
     "style-loader": "2.0.0",
     "webpack": "4.46.0",