lang/ruby32: Mark DEPRECATED and set EXPIRATION_DATE

Default version of Ruby has changed to 3.3. And Ruby 3.2 series has
already switch to security fix only phase with the release of
3.2.8. So mark DEPRECATED to encourage user to migrate to newer
version,

History shows that upstream has released the last version of each
series after the planed EoL date. So set EXPIRATION_DATE to
2026-04-30, one month after the day.

Approved by: self (with hat of ruby)