Added env support to enable/disable gql introspection

[Saranya-jena]

Proposed changes

Summarize your changes here to communicate with the maintainers and make sure to put the link of that issue

Added an env to enable/disable the graphql introspection and by default it will be disabled.

Types of changes

What types of changes does your code introduce to Litmus? Put an x in the boxes that apply

• New feature (non-breaking change which adds functionality)
• Bugfix (non-breaking change which fixes an issue)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation Update (if none of the other choices applies)

Checklist

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• I have read the CONTRIBUTING doc
• I have signed the commit for DCO to be passed.
• Lint and unit tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works (if appropriate)
• I have added necessary documentation (if appropriate)

Dependency

• Please add the links to the dependent PR need to be merged before this (if any).

Special notes for your reviewer:

[Jonsy13]

Do we need nil check here? Already check above

[Saranya-jena]

since line 125 is not in else, even after err is not nil control will still come to line 125 as I am not returning the err in line in 123 😅

[Jonsy13]

Okay got it!

[ispeakc0de]

else-if can help here

[Jonsy13]

Looks good, Thanks!! 🚀