Some room versions are incorrectly assumed to be v12

[velikopter]

Describe the bug

Some rooms versions, like org.matrix.msc3757.10, make Cinny believe that we are creating a v12 room, when we are not:

Rooms with these versions that already exist show the v12 PLs in the sidebar, and in the PL management interface:

Reproduction

1. Go to the room creation menu
2. Click "Advance options" (should be corrected to "Advanced options")
3. Change room version to org.matrix.msc3757.10

Expected behavior

Only v12 rooms present the view for v12 rooms.

Platform and versions

OS: Arch Linux
Browser: Firefox 142.0
Cinny version: Latest commit on the `dev` branch
Server: faelix.im (Synapse 1.136.0)

Additional context

No response

[ajbura]

These versions are unstable and not part of spec thus Cinny doesn't have support for them. On Cinny end a good fix can be to display the "stabe", "unstable" label in room version selector.