Xcode warning: “no rule to process file”

### Description

I followed the [tutorial](https://swiftpackageindex.com/apple/swift-openapi-generator/1.13.0/tutorials/swift-openapi-generator/clientxcode) to generate a client inside Xcode. The client is successfully generated but Xcode shows two warnings:
> no rule to process file '/Users/fumoboy007/Downloads/OpenAPIGenerator-NoRuleToProcessFileWarningRepro/OpenAPIGenerator-NoRuleToProcessFileWarningRepro/openapi-generator-config.yaml' of type 'text.yaml' for architecture 'arm64'
>
> no rule to process file '/Users/fumoboy007/Downloads/OpenAPIGenerator-NoRuleToProcessFileWarningRepro/OpenAPIGenerator-NoRuleToProcessFileWarningRepro/openapi.yaml' of type 'text.yaml' for architecture 'arm64'

### Reproduction

[OpenAPIGenerator-NoRuleToProcessFileWarningRepro.zip](https://github.com/user-attachments/files/31164664/OpenAPIGenerator-NoRuleToProcessFileWarningRepro.zip)

### Package version(s)

swift-openapi-generator 1.13.0

### Expected behavior

No Xcode warnings.

### Environment

Xcode 26.3 (17C529)

### Additional information

Similar issue: #780.

Open the attached OpenAPIGenerator-NoRuleToProcessFileWarningRepro.zip in Xcode 26.3 and reproduce the warnings while following the linked client tutorial. Trace how the generated client and its YAML inputs are included in the package/build, then compare with related issue #780. Done means the client still generates successfully and Xcode reports no “no rule to process file” warnings.

Written by the indexing model from the issue text.