graphql-request: make variables parameter optional in defaultWrapper

[mtlewis]

🚨 IMPORTANT: Please do not create a Pull Request without creating an issue first.

Any change needs to be discussed before proceeding. Failure to do so may result in the rejection of
the pull request.

Description

Please include a summary of the change and which issue is fixed. Please also include relevant
motivation and context. List any dependencies that are required for this change.

Related #558

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as
  expected)
• This change requires a documentation update

Screenshots/Sandbox (if appropriate/relevant):

Adding links to sandbox or providing screenshots can help us understand more about this PR and take
action on it as appropriate

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can
reproduce. Please also list any relevant details for your test configuration

• Unit tests are passing

Test Environment:

• OS:
• @graphql-codegen/...:
• NodeJS:

Checklist:

• I have followed the
  CONTRIBUTING doc and the
  style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

Further comments

If this is a relatively large or complex change, kick off the discussion by explaining why you chose
the solution you did and what alternatives you considered, etc...

[changeset-bot]

🦋 Changeset detected

Latest commit: fc31669

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@graphql-codegen/typescript-graphql-request	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[saihaj]

makes sense

[saihaj]

Released @graphql-codegen/typescript-graphql-request@6.2.0 🚀