Fix ERB deprecated warnings in Ruby 3

[nivla]

• This PR fixes the following deprecated warnings:
  • Passing trim_mode with the 3rd argument of ERB.new is deprecated. Use keyword argument like ERB.new(str, trim_mode: ...) instead.
  • Passing safe_level with the 2nd argument of ERB.new is deprecated. Do not use it, and specify other arguments as keyword arguments

We're going to drop Ruby 2.5 from the CI matrix, right?

[aharpervc]

We're going to drop Ruby 2.5 from the CI matrix, right?

Yes. Is this change safe for 2.7+ or do we need to do like "if ruby_version < 3"...? I see the CI jobs are passing, so I'm mainly asking about the deprecation notices for this code

[nivla]

Yes. Is this change safe for 2.7+ or do we need to do like "if ruby_version < 3"...? I see the CI jobs are passing, so I'm mainly asking about the deprecation notices for this code

Yes, this change is safe for 2.7+, the deprecation warning is no longer present on 2.7, we may need the 'if ruby_version <= 2.5' if we want to apps that use this gem and are still in 2.5.

[aharpervc]

Can you rebase this & confirm it's ready for review? Putting back in draft mode for the moment, feel free to re-enable whenever you want