Fixes broken tests in CI due ruby version and minor improvements

[VictorSNA]

Description

Fix tests that are broken in CI due ruby version by removing freeze from literal string.
Also, added linter step to CI, ignored .gems/ folder, updated build badge to point to github actions and removed duplicated bundle install.

Type of branch

Hotfix

Type of change

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

Running in forked repo CI.

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules