fix: reformat json to yaml based on workflow.yaml (#1612)

Given the following workflow, `out.openapi.yaml` would end up being JSON
when in fact it should be YAML based on the suffix. [GEN-1841: bug:
workflow does not respect `yaml`
extension](https://linear.app/speakeasy/issue/GEN-1841/bug-workflow-does-not-respect-yaml-extension)

```yaml
workflowVersion: 1.0.0
speakeasyVersion: latest
sources:
    petstore-oas:
        inputs:
            - location: openapi.json
        output: .speakeasy/out.openapi.yaml
        registry:
            location: registry.speakeasyapi.dev/speakeasy-self/speakeasy-self/petstore-oas
targets:
    petstore:
        target: typescript
        source: petstore-oas
        codeSamples:
            registry:
                location: registry.speakeasyapi.dev/speakeasy-self/speakeasy-self/petstore-oas-typescript-code-samples
            labelOverride:
                fixedValue: Typescript (SDK)
            blocking: false

```

Author: mfbx9da4

internal/run/source.go

@@ -315,14 +315,18 @@ func writeToOutputLocation(ctx context.Context, documentPath string, outputLocat
 		return err
 	}
 
-	// If we have yaml and need json, convert it
-	if utils.HasYAMLExt(documentPath) && !utils.HasYAMLExt(outputLocation) {
-		jsonBytes, err := schemas.Format(ctx, documentPath, false)
+	// Check if we need to convert between formats based on file extensions
+	sourceIsYAML := utils.HasYAMLExt(documentPath)
+	targetIsYAML := utils.HasYAMLExt(outputLocation)
+
+	// If formats differ, convert appropriately
+	if sourceIsYAML != targetIsYAML {
+		formattedBytes, err := schemas.Format(ctx, documentPath, targetIsYAML)
 		if err != nil {
 			return fmt.Errorf("failed to format document: %w", err)
 		}
 
-		return os.WriteFile(outputLocation, jsonBytes, 0o644)
+		return os.WriteFile(outputLocation, formattedBytes, 0o644)
 	} else {
 		// Otherwise, just copy the file over
 		return utils.CopyFile(documentPath, outputLocation)