Tailored Flows: Unlaunched sites are redirected to `/start`

[mmtr]

Steps to reproduce

• Go to wordpress.com/sites
• Pick a site created with the (now obsolete) free flow

Current behavior

• I'm redirected to /start/free which doesn't make sense because I don't want to create a site

Screen.Recording.2024-10-24.at.12.17.54.mov

Expected behavior

I should land on either the stepper launchpad or My Home

Screen.Recording.2024-10-24.at.12.19.09.mov

[mmtr]

I should land on either the stepper launchpad or My Home

In p1729765539464299-slack-C04DZ8M0GHW we discussed that going to /setup/:flow/launchpad for a removed flow, should mark the launchpad as skipped and redirect the user back to My Home.