[semver:minor] Composer install version

[droath]

Checklist

• [x] All new jobs, commands, executors, parameters have descriptions
• [x] Examples have been added for any significant new features
• [x] README has been updated, if necessary

Motivation, issues

Due to composer releasing 2.0 as the stable release, any PHP projects that have composer plugin using V1 of the API are erroring out. Which drives this need of needing a way to define a composer install version parameter.

Description

Based on how composer-setup.php was developed. The --version definition needs to be based on a semantic version spec. I had to use a when condition to determine if the composer install-version parameter was defined or not, as passing in an empty string or boolean values are not supported.

[gmemstr]

Some funkiness in the pipeline right now, will review shortly :)