Maven deploys failing

[cpswan]

Describe the bug

For a little while now the Maven workflow has been failing:

gpg: no default secret key: No secret key
gpg: signing failed: No secret key
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  14.425 s
[INFO] Finished at: 2024-10-08T08:52:18Z
[INFO] ------------------------------------------------------------------------
Error:  Failed to execute goal org.apache.maven.plugins:maven-gpg-plugin:3.0.1:sign (sign-artifacts) on project at_client: Exit code: 2 -> [Help 1]
Error:  
Error:  To see the full stack trace of the errors, re-run Maven with the -e switch.
Error:  Re-run Maven using the -X switch to enable full debug logging.
Error:  
Error:  For more information about the errors and possible solutions, please read the following articles:
Error:  [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException
Error: Process completed with exit code 1.

Steps to reproduce

1. First I merge a (Dependabot) PR
2. Then the Maven Deploy `at_client` to Nexus OSSRH workflow runs.
3. And then it fails, sending out an alert email.

Expected behavior

Maven Deploy completes sucessfully

Additional context

Logs from the last successful run aren't available any more