(CAT-1606) - Adding gem group for release_pre

[Ramesh7]

Summary

We have multiple use cases where we are installing all gems every time which also lead to installing old gems or conflicts, so creating release_prep for releasing the module.

Checklist

• 🟢 Spec tests.
• 🟢 Acceptance tests.
• Manually verified.

[david22swan]

LGTM

[cocker-cc]

Since this PR pdk validate states:

Your Gemfile lists the gem puppet-strings (~> 4.0) more than once.
You should probably keep only one of them.
Remove any duplicate entries and specify the gem only once.
While it's not a problem now, it could cause errors if you change the version of one of them later.

Your Gemfile lists the gem puppetlabs_spec_helper (~> 6.0) more than once.
You should probably keep only one of them.
Remove any duplicate entries and specify the gem only once.
While it's not a problem now, it could cause errors if you change the version of one of them later.