Update dependency me.modmuss50.mod-publish-plugin to v0.8.4 (#3027)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

gradle/libs.versions.toml

@@ -51,7 +51,7 @@ mockito = "5.14.2"
 
 # Gradle plugins
 pluginyml = "0.6.0"
-mod-publish-plugin = "0.8.1"
+mod-publish-plugin = "0.8.4"
 
 [libraries]
 # Minecraft expectations