Update dfetch/reporting/sbom_reporter.py

Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

Author: spoorcc

dfetch/reporting/sbom_reporter.py

@@ -482,7 +482,10 @@ def _apply_licenses(component: Component, license_scan: LicenseScanResult) -> No
             noassertion = CycloneDxLicense(
                 id="NOASSERTION",
                 acknowledgement=LicenseAcknowledgement.CONCLUDED,
-                text=AttachedText(content=acknowledgement_text),
+                text=AttachedText(
+                    content=acknowledgement_text,
+                    content_type="text/plain",
+                ),
             )
             component.licenses.add(noassertion)
             if component.evidence: