Replace usages of `has_key` with `in` operator of puppet language

[Hedius]

Hi Bernd,

with stdlib 9.0.0 puppetlabs removed the has_key function from the library.

https://github.com/puppetlabs/puppetlabs-stdlib/pull/1319

https://forge.puppet.com/modules/puppetlabs/stdlib/changelog#v900---2023-05-30

The attached commit replaces the usages of has_key with the 'x' in $hash expression.

After fixing this I can use the module fine with the latest version of all dependencies:

• stdlib 9.2.0
• concat 9.0.0
• vcsrepo 6.1.0

Edit: still should work with older versions too since the in expression has been around for ages.

LG, Flo :)