Fix detecting exec js version by adding minimal requirement for autoprefixer-rails

[waiting-for-dev]

Fixes #4055

Checklist:

• I have followed Pull Request guidelines
• I have added a detailed description into each commit message
• I have updated Guides and README accordingly to this change (if needed)
• I have added tests to cover this change (if needed)
• I have attached screenshots to this PR for visual changes (if needed)

[kennyadsl]

How does this play with #4072? Are they supposed to be alternative PRs or do we need both?

[waiting-for-dev]

How does this play with #4072? Are they supposed to be alternative PRs or do we need both?

They are independent and only tangentially related:

• execjs released a new version compatible with ruby 3
• The new version broke autoprefixer-rails
• autoprefixer-rails released a new version locking to the old execjs version (remember, not compatible with ruby 3)
• autoprefixer-rails released another new version fixing the issue for both 3 >= ruby < 3
• This issue makes the last autoprefixer-rails release the minimal version to use
• Support Ruby 3 #4072 makes solidus compatible with ruby 3

[kennyadsl]

Makes sense, thanks for the detailed clarification!

[spaghetticode]

@waiting-for-dev thanks!