devel/py-dj50-strawberry-graphql: Fix handling for CHANNELS option

• The CHANNELS option, if enabled, installs www/py-channels, which pulls in www/py-django42. The latter one conflicts with the DJANGO option, which installs www/py-django50, if enabled.
  
  Fix this issue by adjusting the CHANNELS option use the recently added www/py-dj50-channels, which uses www/py-django50, as a dependency.

• Bump PORTREVISION due changed dependencies.

Co-authored-by: Kai Knoblich <kai@FreeBSD.org>
PR: 283045
Reported by: James TD Smith
MFH: 2024Q4

(cherry picked from commit c0390c7452bc8ec51e51f4e9cbd9db591bbe3746)