Use c12 for wider configuration file format support

[smorimoto]

Closes #1140

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🦋 Changeset detected

Latest commit: f5a5f76

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

This PR includes changesets to release 1 package

Name	Type
swagger-typescript-api	Minor

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[Copilot]

Pull Request Overview

This pull request refactors custom configuration loading by replacing the URL-based import and logging with the loadConfig function from the c12 package, enabling support for a wider configuration file format.

• Replace URL-based custom configuration loading with c12's loadConfig.
• Remove now-unused dependencies (node:url and consola).
• Update the changeset file to document the minor version update for swagger-typescript-api.

Reviewed Changes

Copilot reviewed 3 out of 4 changed files in this pull request and generated no comments.

File	Description
index.ts	Refactored configuration loading by using c12’s loadConfig.
.changeset/fancy-actors-wait.md	Updated changeset with a minor version bump and descriptive text.

Files not reviewed (1)

• package.json: Language not supported

Comments suppressed due to low confidence (1)

index.ts:335

• Ensure that loadConfig returns an object with a valid 'config' property before spreading it. Consider adding a check or a default value to handle cases where custom configuration may be absent.

      ...customConfig.config,