chore: add oapi-codegen

[samirkape]

Useful utility to generate go models based on openapi spec

Please check if what you want to add to awesome-go list meets quality standards before sending pull request. Thanks!

Please provide package links to:

• repo link (github.com, gitlab.com, etc): https://github.com/deepmap/oapi-codegen
• pkg.go.dev: https://pkg.go.dev/github.com/deepmap/oapi-codegen/pkg/codegen
• goreportcard.com: https://goreportcard.com/report/github.com/deepmap/oapi-codegen
• coverage service link (codecov, coveralls, etc.):

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• The package has been added to the list in alphabetical order.
• The package has an appropriate description with correct grammar.
• As far as I know, the package has not been listed here before.
• The repo documentation has a pkg.go.dev link.
• The repo documentation has a coverage service link.
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[phanirithvij]

Can you change the category? This doesn't belong in geographical tools.

[samirkape]

Done