After T342617: Make old columns of externallinks nullable and T342683: Stop writing to the old externallinks columns in beta cluster and production are done for a wiki
Done for testwiki, ongoing for ruwikinews
Progress:
- s1: Done
- s2: Done
- s3: Done
- s4: Done
- s5: Done
- s6: Done
- s7: Done
- s8: Done
- labtestwiki