set githubWorkflowScalaVersions to a fake value since sbt-projectmatr…

…ix controls the version on a per-project basis

.github/workflows/ci.yml

@@ -28,7 +28,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest]
-        scala: [2.13, 2.12]
+        scala: [per-project-matrix]
         java: [temurin@8]
     runs-on: ${{ matrix.os }}
     timeout-minutes: 60
@@ -108,22 +108,12 @@ jobs:
         if: matrix.java == 'temurin@8' && steps.setup-java-temurin-8.outputs.cache-hit == 'false'
         run: sbt +update
 
-      - name: Download target directories (2.13)
+      - name: Download target directories (per-project-matrix)
         uses: actions/download-artifact@v4
         with:
-          name: target-${{ matrix.os }}-${{ matrix.java }}-2.13
+          name: target-${{ matrix.os }}-${{ matrix.java }}-per-project-matrix
 
-      - name: Inflate target directories (2.13)
-        run: |
-          tar xf targets.tar
-          rm targets.tar
-
-      - name: Download target directories (2.12)
-        uses: actions/download-artifact@v4
-        with:
-          name: target-${{ matrix.os }}-${{ matrix.java }}-2.12
-
-      - name: Inflate target directories (2.12)
+      - name: Inflate target directories (per-project-matrix)
         run: |
           tar xf targets.tar
           rm targets.tar

.mergify.yml

@@ -12,8 +12,7 @@ pull_request_rules:
   - or:
     - body~=labels:.*early-semver-patch
     - body~=labels:.*early-semver-minor
-  - status-success=Build and Test (ubuntu-latest, 2.13, temurin@8)
-  - status-success=Build and Test (ubuntu-latest, 2.12, temurin@8)
+  - status-success=Build and Test (ubuntu-latest, per-project-matrix, temurin@8)
   - status-success=Validate Steward Config (ubuntu-latest, temurin@11)
   actions:
     merge: {}

build.sbt

@@ -12,7 +12,6 @@ ThisBuild / developers := List(
 ThisBuild / startYear := Option(2021)
 ThisBuild / tlSonatypeUseLegacyHost := true
 ThisBuild / tlBaseVersion := "1.1"
-ThisBuild / githubWorkflowScalaVersions := Seq("2.13", "2.12")
 ThisBuild / tlCiReleaseBranches := Seq("main")
 ThisBuild / mergifyRequiredJobs ++= Seq("validate-steward")
 ThisBuild / mergifyStewardConfig ~= { _.map(_.copy(

project/AsyncUtilsBuildPlugin.scala

@@ -7,7 +7,12 @@ import org.scalajs.jsenv.nodejs.NodeJSEnv
 import org.scalajs.sbtplugin.ScalaJSPlugin.autoImport.*
 import org.typelevel.sbt.TypelevelMimaPlugin.autoImport.*
 import org.typelevel.sbt.TypelevelSettingsPlugin
+import org.typelevel.sbt.TypelevelSettingsPlugin.autoImport.*
+import org.typelevel.sbt.TypelevelSonatypeCiReleasePlugin.autoImport.*
+import org.typelevel.sbt.TypelevelSonatypePlugin.autoImport.*
+import org.typelevel.sbt.TypelevelVersioningPlugin.autoImport.*
 import org.typelevel.sbt.gha.GenerativePlugin.autoImport.*
+import org.typelevel.sbt.gha.GitHubActionsPlugin.autoImport.*
 import org.typelevel.sbt.mergify.MergifyPlugin
 import org.typelevel.sbt.mergify.MergifyPlugin.autoImport.*
 import sbt.*
@@ -318,20 +323,7 @@ object AsyncUtilsBuildPlugin extends AutoPlugin {
         .map(x => x -> file(x))
         .toMap,
 
-    /* this is misleading, because we're actually running the build for all supported
-     * scala versions, but unfortunately this seems to be our best option until
-     * sbt-typelevel 0.5.
-     *
-     * sbt-projectmatrix creates separate projects for each crossed Scala version
-     * setting githubWorkflowScalaVersions to a single (ignored) version minimizes
-     * the build matrix, and setting githubWorkflowBuildSbtStepPreamble to an empty
-     * list ensures that the build phase ignores the scala version set in
-     * githubWorkflowScalaVersions.
-     *
-     * '++ ${{ matrix.scala }}' will still be used in the Publish stage, but it
-     * sounds like the tlCiRelease will do the right thing anyway.
-     */
-    githubWorkflowScalaVersions := Seq("2.13"),
+    githubWorkflowScalaVersions := Seq("per-project-matrix"),
     githubWorkflowBuildSbtStepPreamble := Nil,
 
     nodeExecutable :=