chore(evaluated-model): Remove a superfluous file format case

As of 78fb986 `FileFormat` only has `JSON` and `YAML` entries, so the
`when` clause is exhausitve and the `else` branch can be removed.

Signed-off-by: Sebastian Schuberth <sebastian@doubleopen.org>

plugins/reporters/evaluated-model/src/main/kotlin/EvaluatedModelReporter.kt

@@ -62,7 +62,6 @@ class EvaluatedModelReporter : Reporter {
                 when (fileFormat) {
                     FileFormat.JSON -> evaluatedModel.toJson(it)
                     FileFormat.YAML -> evaluatedModel.toYaml(it)
-                    else -> throw IllegalArgumentException("Unsupported Evaluated Model file format '$fileFormat'.")
                 }
             }