WS-601: fixing potential sites of UnboundLocalError

• fixed a couple potential (one actual) sites of UnboundLocalError
• turned a few magic strings into constants

apps/cli/executables/pexable/ingest_envoy/ingest_envoy/manifest_components.py

@@ -16,8 +16,6 @@ WEBLOG_FILENAME = "weblog.tgz"
 SCIENCE_PRODUCT_PATTERN = re.compile("[a-zA-Z0-9._\\-+]*\\.tar")
 JSON = Union[int, float, str, List["JSON"], Dict[str, "JSON"]]
 
-print()
-
 
 class IngestionManifestKey(Enum):
     """Sections we expect to see in a manifest"""