Provide config.xsd for psalm/phar composer package

[boesing]

Hey there,
I wonder if it is possible to have the config.xsd file available from within this package?

I do maintain https://github.com/laminas/laminas-ci-matrix-action which does detect psalm.xml/psalm.xml.dist.
As of now, we assume that once that config file is available, vimeo/psalm will be installed afterwards. Though we register a CI job for static analysis via psalm which executes a previous check which verifies that the psalm.xml matches config.xsd requirements via xmllint --schema vendor/vimeo/psalm/config.xsd psalm.xml.

We do have a feature request to also support psalm/phar. I was thinking about a way how we could properly support that and came up with the fact that we should relocate the config.xsd in that case to vendor/psalm/phar/config.xsd instead but the file is not bundled during package generation.

Could some1 target me to the project/workflow which generates the PHAR so that I can provide a patch where the config.xsd is bundled in upcoming versions? I do not expect this to be handled for already released versions but I think it could provide some benefits for future usage of this package.

[zonuexe]

Related PR: vimeo/psalm#10938