Build: Fix artifacts signing for maven central

With gradle > 5.0 `publish()` helper call should be done before
`noDefaultJar()` or any other artifact hacks, otherwise singing plugin doesn't sign any jars

plugins/kapt3/kapt3-compiler/build.gradle.kts

@@ -50,6 +50,8 @@ projectTest {
     dependsOn(":dist")
 }
 
+publish()
+
 runtimeJar {
     fromEmbeddedComponents()
 }
@@ -58,5 +60,3 @@ sourcesJar()
 javadocJar()
 
 dist()
-
-publish()