javadoc nits

[elharo]

Testing whether the CI is broken. Nothing in this PR should fail any test.

@timtebeek

[elharo]

Verify / Verify / windows-latest jdk-8-temurin 3.9.2 (push) is broken:

Error:  Failures: 
Error:    GpgSignArtifactIT.testPlacementOfArtifactInOutputDirectory:98 
Expected: ["sign-release-in-default-dir-1.0.jar.asc"] in any order
     but: no item matches: "sign-release-in-default-dir-1.0.jar.asc" in []
Error:    GpgSignArtifactIT.testPlacementOfArtifactInOutputDirectory:98 
Expected: ["sign-release-in-output-dir-1.0.jar.asc"] in any order
     but: no item matches: "sign-release-in-output-dir-1.0.jar.asc" in []
Error:    GpgSignArtifactIT.testPlacementOfArtifactInOutputDirectory:98 
Expected: ["sign-release-in-root-dir-1.0.jar.asc"] in any order
     but: no item matches: "sign-release-in-root-dir-1.0.jar.asc" in []
Error:    GpgSignArtifactIT.testPlacementOfArtifactInOutputDirectory:98 
Expected: ["sign-release-in-same-dir-1.0.jar", "sign-release-in-same-dir-1.0.jar.asc"] in any order
     but: no item matches: "sign-release-in-same-dir-1.0.jar.asc" in ["sign-release-in-same-dir-1.0.jar"]
Error:    GpgSignAttachedMojoIT.testInteractiveWithoutPassphrase:64 Maven execution failed because no pinentry program is available
Expected: a string containing "[GNUPG:] FAILURE sign 67108949"
     but: was "[DEBUG] Using maven.home of: 'C:\Users\runneradmin\.m2\wrapper\dists\apache-maven-3.9.2-bin\3238cb54\apache-maven-3.9.2'.
[DEBUG] Executing: cmd.exe /X /C "C:\Users\runneradmin\.m2\wrapper\dists\apache-maven-3.9.2-bin\3238cb54\apache-maven-3.9.2\bin\mvn.cmd -X -V -D maven.repo.local=D:\a\maven-gpg-plugin\maven-gpg-plugin\target\local-repo -s D:\a\maven-gpg-plugin\maven-gpg-plugin\target\test-classes\it\settings.xml -D gpg.homedir=D:\a\maven-gpg-plugin\maven-gpg-plugin\target\test-classes\gnupg clean install"