there is not much beyond the snippet:
pkgutil --check-signature /xxxx/Glean-1.0.0-universal.pkg
Package "xxx-1.0.0-universal.pkg":
Status: signed by a certificate that has since expired
Certificate Chain:
1. 3rd Party Mac Developer Installer: XXXX
Expires: 2024-06-01 22:33:34 +0000
SHA256 Fingerprint:
CODES...
Topic:
Code Signing
SubTopic:
Certificates, Identifiers & Profiles
Tags: