Apply new Shipkit Changelog plugin properties

Recently there were added 2 new properties to Shipkit Changelog plugin:
1. 'newTagRevision' that ensures predictable tagging. 'GITHUB_SHA' that supplies the property, is an GH Action's env variable that exposes SHA of the commit that triggered the workflow.
2. Token that is set by 'githubToken' property is used both to fetch and post via GH API. Earlier used 'readOnlyToken' and 'writeToken' properties are now deprecated.

Author: shestee

gradle/shipkit.gradle

@@ -5,7 +5,7 @@ apply plugin: "org.shipkit.shipkit-gh-release"
 
 tasks.named("generateChangelog") {
     previousRevision = project.ext.'shipkit-auto-version.previous-tag'
-    readOnlyToken = System.getenv("GITHUB_TOKEN")
+    githubToken = System.getenv("GITHUB_TOKEN")
     repository = "mockito/mockito-testng"
 }
 
@@ -14,5 +14,6 @@ tasks.named("githubRelease") {
     dependsOn genTask
     repository = genTask.repository
     changelog = genTask.outputFile
-    writeToken = System.getenv("GITHUB_TOKEN")
+    githubToken = System.getenv("GITHUB_TOKEN")
+    newTagRevision = System.getenv("GITHUB_SHA")
 }