Check for template placeholders.

The nf-core create pipeline template uses Jinja behind the scenes.

This lint test fails if any Jinja template variables such as {{ pipeline_name }} are found in your pipeline code.

Finding a placeholder like this means that something was probably copied and pasted from the template without being properly rendered for your pipeline.

This test ignores any double-brackets prefixed with a dollar sign, such as ${{ secrets.AWS_ACCESS_KEY_ID }} as these placeholders are used in GitHub Actions workflows.