Bump twbs/bootstrap from 4.6.2 to 5.3.8

Bumps [twbs/bootstrap](https://github.com/twbs/bootstrap) from 4.6.2 to 5.3.8.
- [Release notes](https://github.com/twbs/bootstrap/releases)
- [Commits](twbs/bootstrap@v4.6.2...v5.3.8)

---
updated-dependencies:
- dependency-name: twbs/bootstrap
  dependency-version: 5.3.8
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

composer.json

@@ -26,7 +26,7 @@
     "components/jquery": "3.5.*",
     "phpmailer/phpmailer": "6.8.*",
     "tinymce/tinymce": "7.7.*",
-    "twbs/bootstrap": "4.6.*",
+    "twbs/bootstrap": "5.3.*",
     "twbs/bootstrap-icons": "1.10.*"
   },
   "require-dev": {