refactor(helper-cli): Adjust return type of getScannedProvenance()

Simplify an upcoming change.

Signed-off-by: Frank Viernau <[email protected]>

helper-cli/src/main/kotlin/utils/Extensions.kt

@@ -229,8 +229,8 @@ internal fun OrtResult.getViolatedRulesByLicense(
 /**
  * Return the [Provenance] of the first scan result matching the given [id] or null if there is no match.
  */
-internal fun OrtResult.getScannedProvenance(id: Identifier): Provenance? =
-    getScanResultsForId(id).firstOrNull()?.provenance
+internal fun OrtResult.getScannedProvenance(id: Identifier): KnownProvenance? =
+    getScanResultsForId(id).firstNotNullOfOrNull { it.provenance as? KnownProvenance }
 
 /**
  * Return all issues from scan results. Issues for excludes [Project]s or [Package]s are not returned if and only if