Use --no-check-publish in php-composer-validate, create php-composer-package…


Use --no-check-publish in php-composer-validate, create php-composer-package-validate

For extensions and other things that want to use composer for development
dependencies and a test entry point, the php-composer-validate checks the
basic schema of the file.

For libraries that are published on packagist.org, the
php-composer-validate-package job has a few more checks against the schema.

Bug: T91176
Change-Id: Ib1305c8ee04a56ae7b1fecafbdba13945848c534