Add script to update inner Scala versions

.scala-steward.conf

@@ -1,7 +1,21 @@
-postUpdateHooks = [{
-  command = ["./update-inner-workflows.sh"],
-  commitMessage = "Regenerated inner workflows",
-  groupId = "org.typelevel",
-  artifactId = "sbt-typelevel"
-}]
+postUpdateHooks = [
+  {
+    command = ["./update-inner-workflows.sh"],
+    commitMessage = "Regenerated inner workflows",
+    groupId = "org.typelevel",
+    artifactId = "sbt-typelevel"
+  },
+  {
+    command = ["./update-scala-versions.sh"],
+    commitMessage = "Synced Scala 2.13 version to inner template",
+    groupId = "org.scala-lang",
+    artifactId = "scala-library"
+  },
+  {
+    command = ["./update-scala-versions.sh"],
+    commitMessage = "Synced Scala 3 version to inner template",
+    groupId = "org.scala-lang",
+    artifactId = "scala3-library_3"
+  }
+]
 updates.fileExtensions = [".scala", ".sbt", ".properties", ".md"]

update-scala-versions.sh

@@ -0,0 +1,22 @@
+#!/usr/bin/env bash
+# exit when any command fails
+set -e
+
+echo "Syncing Scala versions from build.sbt to default.properties"
+SCALA2_VERSION=$(grep 'scala-library' build.sbt | grep -o '"2.13.[0-9]\+"' | tr -d '"')
+SCALA3_VERSION=$(grep 'scala3-library_3' build.sbt | grep -o '"3.[0-9]\+.[0-9]\+"' | tr -d '"')
+
+if [ -z "$SCALA2_VERSION" ] || [ -z "$SCALA3_VERSION" ]; then
+  echo "Error: Could not extract Scala versions from build.sbt"
+  exit 1
+fi
+echo "Found Scala 2 version: $SCALA2_VERSION"
+echo "Found Scala 3 version: $SCALA3_VERSION"
+
+# Update default.properties
+sed -i.bak "s/scala_version = [0-9.]*/scala_version = $SCALA2_VERSION/" src/main/g8/default.properties
+sed -i.bak "s/other_scala_version = [0-9.]*/other_scala_version = $SCALA3_VERSION/" src/main/g8/default.properties
+rm -f src/main/g8/default.properties.bak
+
+echo "Updated src/main/g8/default.properties"
+