ukify: show .sbom sections as binary

Fixup for e87dec82be:
I misunderstood the format. It's actually CBOR, i.e. some binary format.
When trying to show show text we would first check if it's valid UTF-8,
so we would handle this gracefully, i.e. emit a warning and not print
the contents.

src/ukify/ukify.py

@@ -265,7 +265,7 @@ DEFAULT_SECTIONS_TO_SHOW = {
         '.pcrpkey'  : 'text',
         '.pcrsig'   : 'text',
         '.sbat'     : 'text',
-        '.sbom'     : 'text',
+        '.sbom'     : 'binary',
 }
 
 @dataclasses.dataclass