Add non ASCII encoding schema support to RailsSchemaUpToDate hook

[ttrmw]

Adds the possibility of adding an encoding config item if you know your schema.rb or structure.sql file contains non ASCII characters, as in the case of the project I'm working on :grin:

It's possible you might also want this on migration files, but I haven't included that in this PR, let me know if that's something you'd like to see to get this merged.

[sds]

Hey @ttrmw, sorry for the delay in response.

It looks like the Ruby 3 tests are failing with real errors. There are also some spurious errors (timeouts) that can be ignored, but happy to merge once the Ruby 3 tests are passing. Thanks!

[ttrmw]

Thanks! Will take a look at repro locally and push a fix.

[ttrmw]

Hiya, my turn for a huge delay. @pajw has sorted the test failures out - please rerun CI at your convenience :grin:

[sds]

Sorry for the delay. Failures seem unrelated to your changes, going to go ahead and merge.