Set inceptionYear for Maven publication.

Author: nstdio

buildSrc/src/main/kotlin/io.github.nstdio.http.ext.publish-conventions.gradle.kts

@@ -35,6 +35,7 @@ publishing {
         name.set("JDK Http Client Extensions")
         description.set("The set of useful extensions for JDK HttpClient.")
         url.set("https://github.com/nstdio/http-client-ext")
+        inceptionYear.set("2021")
 
         licenses {
           license {