Optimize release-files-spec.json for *.zip.asc

The Maven Central does not accept zip files.
We skip them from Artifactory downloading.
However, we still download signature (`.asc`) for those zips.
`
* Modify `release-files-spec.json` for the extra `and` entry to avoid `*.zip.asc`
from Artifactory downloading.
And therefore they are not going to be uploaded to Maven Central

utils/release-files-spec.json

@@ -34,6 +34,11 @@
                   }
                 }
               ]
+            },
+            {
+              "name": {
+                "$nmatch": "*.zip.asc"
+              }
             }
           ]
         }