feat: SPDX 2.3 support (#1311)

syft/formats/spdxjson/format.go

@@ -0,0 +1,17 @@
+package spdxjson
+
+import (
+	"github.com/anchore/syft/syft/sbom"
+)
+
+const ID sbom.FormatID = "spdx-2-json"
+
+// note: this format is LOSSY relative to the syftjson format
+func Format() sbom.Format {
+	return sbom.NewFormat(
+		ID,
+		encoder,
+		decoder,
+		validator,
+	)
+}