WIP: Adopt scala library release GHA workflow

Following [the example from
play-secret-rotation](guardian/play-secret-rotation#416),
rather than set up a new developer credential to release the next
version of this library, this commit sets up
[guardian/gha-scala-library-release-workflow](https://github.com/guardian/gha-scala-library-release-workflow).

.github/workflows/release.yml

@@ -0,0 +1,13 @@
+name: Release
+
+on:
+  workflow_dispatch:
+
+jobs:
+  release:
+    uses: guardian/gha-scala-library-release-workflow/.github/workflows/reusable-release.yml@main
+    permissions:
+      contents: write
+    secrets:
+      AUTOMATED_MAVEN_RELEASE_PGP_SECRET: ${{ secrets.AUTOMATED_MAVEN_RELEASE_PGP_SECRET }}
+      AUTOMATED_MAVEN_RELEASE_SONATYPE_PASSWORD: ${{ secrets.AUTOMATED_MAVEN_RELEASE_SONATYPE_PASSWORD }}

build.sbt

@@ -1,3 +1,5 @@
+import sbtversionpolicy.withsbtrelease.ReleaseVersion.fromAggregatedAssessedCompatibilityWithLatestRelease
+
 ThisBuild/scalaVersion := "2.13.12"
 
 ThisBuild/crossScalaVersions := Seq(scalaVersion.value)
@@ -6,6 +8,7 @@ val commonSettings = Seq(
   organization := "com.gu",
   homepage := Some(url("https://github.com/guardian/marley")),
   licenses := Seq("Apache V2" -> url("http://www.apache.org/licenses/LICENSE-2.0.html")),
+  releaseVersion := fromAggregatedAssessedCompatibilityWithLatestRelease().value,
   libraryDependencies ++= Seq(
     "org.scala-lang" % "scala-reflect" % scalaVersion.value,
     "com.twitter" %% "scrooge-core" % "22.12.0",
@@ -42,9 +45,7 @@ Test/publishArtifact := false
 
 lazy val root = (project in file(".")).aggregate(core).settings(
   update/aggregate := false,
-  publishArtifact := false,
-  publish := {},
-  publishLocal := {}
+  publish/skip := true,
 )
 
 import ReleaseTransformations._
@@ -60,11 +61,6 @@ releaseProcess := Seq[ReleaseStep](
   setReleaseVersion,
   commitReleaseVersion,
   tagRelease,
-  // For non cross-build projects, use releaseStepCommand("publishSigned")
-  releaseStepCommandAndRemaining("+publishSigned"),
-  releaseStepCommand("sonatypeBundleRelease"),
   setNextVersion,
-  commitNextVersion,
-  pushChanges
+  commitNextVersion
 )
-

project/plugins.sbt

@@ -5,5 +5,5 @@ libraryDependencies += "org.apache.thrift" % "libthrift" % "0.17.0"
 addSbtPlugin("com.twitter" %% "scrooge-sbt-plugin" % "22.12.0")
 
 addSbtPlugin("com.github.sbt" % "sbt-release" % "1.1.0")
-addSbtPlugin("com.github.sbt" % "sbt-pgp" % "2.2.1")
+addSbtPlugin("ch.epfl.scala" % "sbt-version-policy" % "3.2.0")
 addSbtPlugin("org.xerial.sbt" % "sbt-sonatype" % "3.9.21")

sonatype.sbt

@@ -1,9 +1,5 @@
 publishMavenStyle := true
 
-sonatypeProfileName := "com.gu"
-
-ThisBuild / publishTo := sonatypePublishToBundle.value
-
 ThisBuild / scmInfo := Some(ScmInfo(
   url("https://github.com/guardian/marley"),
   "scm:git:git@github.com:guardian/marley.git"