Dummy "about:" pages are not cleared from recently closed tabs (and possibly elsewhere) because they are normal tabs, not private tabs.

🐞 Bug Report

Reproduction steps

1. Bootstrap
2. Tap on tabs icon
3. Tap on the kebob menu in the top right of the tabs menu
4. Tap on "Recently closed tabs"
5. Notice that there is at least one "about:" tab in the history (likely more since it adds another every time the bootstrap occurs, effectively counting how many times you've bootstrapped)

Expected behaviour

Bootstrap generated "about:" tabs should never be visible to the user

Actual behaviour

Bootstrap generated "about:" tabs are visible to the user

Bookkeeping

• Browser version:
• Browser channel:
  • Release
  • Alpha
  • Nightly
• Distribution method:
  • Installer/archive from torproject.org
  • tor-browser-launcher
  • homebrew
  • other (please specify):
• Operating System:
  • Windows
  • macOS
  • Linux
  • Android
  • Tails
  • Other (please specify):
• Operating System Version:

Do you have any extra extensions installed?

No

Troubleshooting

Does this bug occur in a fresh installation?

Yes

Is this bug new? If it is a regression, in which version of the browser did this bug first appear?

Yes, 14.5 with connection assist

Does this bug occur in the Alpha release channel?

Yes

---