Pipeline fails when project includes another project yaml and compliance yaml

Summary

When the project is configured with custom CI file (gitlab-ci.yml@namespace/group-1/project-1), project pipelines fails with an error “Pipeline cannot be run. Included file .gitlab-ci.yml@namespace/group-1/project-1 does not have YAML extension!”

##Steps to reproduce

1. Create a project group-1/project-1 that has compliance pipeline yaml. For example - base-compliance.gitlab-ci.yaml
2. Create a compliance framework XYZ pointing to the above compliance yaml i.e. base-compliance.gitlab-ci.yaml@group-1/project-1
3. Create another project group-1/project-2 that has the CI pipeline yaml file i.e. common-fragment.gitlab-ci.yaml
4. Create another project group-1/project-3 and update CI/CD configuration file in pipeline settings to use CI file in group-1/project-2 i.e. common-fragment.gitlab-ci.yaml@group-1/project-2
5. Apply compliance framework XYZ to group-1/project-3 and run the pipeline for group-1/project-3

Example project with failing pipeline

What is the current bug behaviour?

The pipeline fails with the following error: Included file common-fragment-gitlab-ci.yml@group-1/project-2 does not have YAML extension!

What is the expected correct behaviour?

The pipeline should run both the compliance framework yaml and the project yaml