Composer-lint fails if there are no php files in the project

Migrated issue

Reported by: grimreaper

Related to !168 (merged)

Problem/Motivation

Hi,

composer-lint job fails while it says that composer.json is valid: https://git.drupalcode.org/project/sobki_theme_admin/-/jobs/1181958

Proposed resolution

The job fails on projects where there are no files that match .php, .inc, .module or .install
So the job can check for the existence of atleast one of these before running parallel-lint

Update doc page

Here is a view of how the updated doc page will appear
https://git.drupalcode.org/issue/gitlab_templates-3436819/-/blob/3436819-no-files-for-parallel-lint/docs/jobs/composer-lint.md