actions: run: shell variables have incorrect paths when in postprocess

[obbardc]

export ARTIFACTDIR='/recipes/out'
export HOME='/tmp'
export PWD='/recipes'
export RECIPEDIR='/recipes'

these paths do not exist in postprocess :-)

[obbardc]

no i am wrong :-)

- postprocess -- if set script or command is executed after all other commands and
has access to the recipe directory ($RECIPEDIR) and the artifact directory ($ARTIFACTDIR).
The working directory will be set to the artifact directory.