Migrate to Portal OSSRH Staging API

The Sonatype OSSRH (OSS Repository Hosting) publishing service
[will be discontinued on 2025-06-30][1] so we need to migrate either
to the [Central Portal Publisher Service][2]
or to the [Portal OSSRH Staging API][3].

The former is a completely new API, the latter is a migratory/shim
(partial reimplementation of the old) API to enable users who are using
existing plugins to have a smooth migration to the
Central Publisher Portal.

The [gradle-nexus/publish-plugin][4] is [supported][5] by the
[Portal OSSRH Staging API][3] so we can use that until the plugin
supports the new Central Portal Publisher Service:
gradle-nexus/publish-plugin#330

[1]: https://central.sonatype.org/news/20250326_ossrh_sunset/
[2]: https://central.sonatype.org/publish/publish-portal-guide/
[3]: https://central.sonatype.org/publish/publish-portal-ossrh-staging-api/
[4]: https://github.com/gradle-nexus/publish-plugin/
[5]: https://central.sonatype.org/publish/publish-portal-ossrh-staging-api/#plugins-tested-for-compatibility

Closes gh-1083
See gradle-nexus/publish-plugin#330

Author: jonatan-ivanov

build.gradle

@@ -327,7 +327,7 @@ subprojects {
 nexusPublishing {
 	repositories {
 		mavenCentral {
-			nexusUrl.set(uri('https://s01.oss.sonatype.org/service/local/'))
+			nexusUrl.set(uri('https://ossrh-staging-api.central.sonatype.com/service/local/'))
 			snapshotRepositoryUrl.set(uri('https://repo.spring.io/snapshot/')) // not used but necessary for the plugin
 			username = findProperty('MAVEN_CENTRAL_USER')
 			password = findProperty('MAVEN_CENTRAL_PASSWORD')