fhir check likely won't ever fail without specifying the --fail flag

[chgl]

In https://github.com/FirelyTeam/firely-terminal-pipeline/blob/main/action.yml#L241, fhir check is ran without specifying the --fail flag. This means that even if validation fails, the action still completes successfully, which is most likely not the expected behavior.

See:

$ fhir validate patient-bundle.json
warning: Evaluation of FhirPath for constraint 'GeburtsdatumRundenAufQuartal' failed: Invocation of function 'matches' failed: Cannot cast from 'Date' to '.NET type String'
error: Instance failed constraint GeburtsdatumRundenAufQuartal "Geburtsdatum darf nicht tagesgenau angegben werden. Das Geburtsdatum MUSS quartalsweise auf-/abgerundet werden."
Result: INVALID

$ echo $?
0

(I can't run check since its a licensed feature, but I believe the commands behave identically).