fix: Set global preferences variables

[se35710]

Using composite runs sets the variables to non-default values, which breaks Excavator (if there is an error in the Excavator workflow run), even if THROW_ERROR is not set.

Example logfile without setting preference variables:

Property '18' does not exist on JObject.
ForEach-Object: C:\Users\runneradmin\SCOOP\apps\scoop\current\lib\json.ps1:130
Line |
 130 |      $jsonpath.split('.') | ForEach-Object {
     |                             ~~~~~~~~~~~~~~~~
     | Cannot index into a null array.

Error: Process completed with exit code 1.