Misc dev + update fixes

[Vauff]

• Updated gamedata for 2026-01-21 CS2 update
• Updated weapon prices for 2026-01-21 CS2 update
• Fixed permanent blood decals not being blocked after 2026-01-21 CS2 update
• Updated SDK for 2026-01-21 CS2 update
• Updated spawnpoint vector types for 2026-01-23 CS2 update
• Fixed missing setuptools in Windows CI
• Fixed rare crash from missing handle validity checks
• Fixed disconnected players grenades being able to damage teammates
• Added map migrations system for automatic CS2 update breakage fixup
  • Initially, this is being used to automatically fix func_door_rotating & rendermode issues after the 2026-01-21 CS2 update
  • This feature will likely be expanded upon in the future when future CS2 updates inevitably change/break more map functionality, at least where possible
  • The fixup only automatically runs on older maps (determined by workshop update time), to prevent introducing breakage on updated maps that probably already account for these changes themselves
  • Servers can override this behaviour where necessary with the cs2f_mapmigrations_20260121 cvar in map configs
• Updated copyright year
• Fixed RTV breaking if an ongoing extend vote succeeds
• Fixed a case where iterating all entities wasn't done correctly
• Updated GoToIntermission offset for 2026-02-04 CS2 update
• Removed legacy knife sounds from !stopsound
  • Many of the new knife sounds from the 2026-01-21 CS2 update seem to be triggered client-side, so unfortunately we can no longer fix this feature by reliably blocking it server-side