Draft: Add a new function in utils.sh to build static jh/Gemfile

What does this MR do and why?

Describe in detail what your merge request does and why.

Per the discussion, we would like to make jh/Gemfile static by getting rid of instance_eval.

1. Rename jh/Gemfile to jh/Gemfile.jh and remove

instance_eval gemfile.gsub('vendor/gems', '../vendor/gems')

This will be done in this JiHu MR.

2. Add a new function in utils.sh

build_static_jh_gemfile can be utilised by gitlab, code-sync and local developers to generate a static jh/Gemfile

Screenshots or screen recordings

Backend change.

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.