ci: configure release build

Author: oliemansm

build.gradle

@@ -134,9 +134,9 @@ subprojects {
         }
 
         if (!version.toString().endsWith('-SNAPSHOT')) {
-            ext["signing.keyId"] = rootProject.ext["signing.keyId"]
-            ext["signing.password"] = rootProject.ext["signing.password"]
-            ext["signing.secretKeyRingFile"] = rootProject.ext["signing.secretKeyRingFile"]
+            ext["signing.keyId"] = System.env.SIGNING_KEY_ID
+            ext["signing.password"] = System.env.SIGNING_PASSWORD
+            ext["signing.secretKeyRingFile"] = System.env.SIGNING_SECRET_KEY_RING_FILE
 
             signing {
                 sign publishing.publications