[Build] Add workflows for automatic releases

publish.gradle

@@ -17,8 +17,8 @@ ext.configurePublishing = { packageName, packageDesc ->
                 def snapshotsRepoUrl = 'https://oss.sonatype.org/content/repositories/snapshots'
                 url = version.endsWith('SNAPSHOT') ? snapshotsRepoUrl : releasesRepoUrl
                 credentials {
-                    username = findProperty('nexusUpdId') ?: ''
-                    password = findProperty('nexusUpdPass') ?: ''
+                    username = System.getenv('NEXUS_UPD_ID')
+                    password = System.getenv('NEXUS_UPD_PASS')
                 }
             }
         }
@@ -59,6 +59,9 @@ ext.configurePublishing = { packageName, packageDesc ->
         }
     }
     signing {
+        def signingKeyId = System.getenv('SIGNING_KEY_ID')
+        def signingKey = System.getenv('SIGNING_KEY')
+        useInMemoryPgpKeys(signingKeyId, signingKey, '')
         sign publishing.publications.mavenJava
     }
 }