chore(): update axios interface

[Tony133]

PR Checklist

Please check if your PR fulfills the following requirements:

• [x] The commit message follows our guidelines: https://github.com/nestjs/terminus/blob/master/CONTRIBUTING.md
• [ ] Tests for the changes have been added (for bug fixes / features)
• [ ] Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

• [ ] Bugfix
• [ ] Feature
• [ ] Code style update (formatting, local variables)
• [ ] Refactoring (no functional changes, no api changes)
• [ ] Build related changes
• [ ] CI related changes
• [x] Other... Please describe:

What is the current behavior?

Issue Number: #2045

What is the new behavior?

Added string type to method parameter in AxiosRequestConfig interface

Does this PR introduce a breaking change?

• [ ] Yes
• [x] No

Other information