When trying to sign my publications, this error appears:

I’m trying to publish my library to the Maven Central Repository, so I’m trying to configure signing for my project. However, when I run the publish task, this error appears in the :signMavenPublication task: gist:05bde5b4ed2b2caf95a5a1f0e4232105 (github.com)

The error is pretty meaningful, isn’t it?
It tried to read your secret keyring file at C:\Users\shach\.gnupg\secring.gpg and was not able to.
So I guess you either broke file permissions for your keyring file, or you maybe did not yet generate keys for signing.