Keep .ruby_version file in Docker

[corsonknowles]

Addresses:

• Use our .ruby-version file in Bundler so it is managed in only 1 place #520 (comment)

[zachgoll]

Good catch @robzolkos, looks like this is the default for rails new now?

[robzolkos]

Good catch @robzolkos, looks like this is the default for rails new now?

No rails new will spit out unchanged Dockerfile

This functionality was reverted in Rails main. I suspect largely due to it being a generator.

I think copying over the .ruby-version prior to the Gemfile should work fine. Maybe is already generated so little risk in smoothing over these edges.

[zachgoll]

Good catch @robzolkos, looks like this is the default for rails new now?

No rails new will spit out unchanged Dockerfile

This functionality was reverted in Rails main. I suspect largely due to it being a generator.

I think copying over the .ruby-version prior to the Gemfile should work fine. Maybe is already generated so little risk in smoothing over these edges.

Ahh, hadn't seen that commit. Sounds good, and we can revisit this with more scrutiny later when implementing #295