ci: split validate workflow

Author: crazy-max

.github/workflows/validate.yml

@@ -8,15 +8,32 @@ on:
     paths-ignore:
       - '**.md'
   pull_request:
-    branches:
-      - 'master'
-      - 'releases/v*'
     paths-ignore:
       - '**.md'
 
 jobs:
+  prepare:
+    runs-on: ubuntu-latest
+    outputs:
+      targets: ${{ steps.targets.outputs.matrix }}
+    steps:
+      -
+        name: Checkout
+        uses: actions/checkout@v3
+      -
+        name: Targets matrix
+        id: targets
+        run: |
+          echo "matrix=$(docker buildx bake validate --print | jq -cr '.group.validate.targets')" >> $GITHUB_OUTPUT
+
   validate:
     runs-on: ubuntu-latest
+    needs:
+      - prepare
+    strategy:
+      fail-fast: false
+      matrix:
+        target: ${{ fromJson(needs.prepare.outputs.targets) }}
     steps:
       -
         name: Checkout
@@ -25,4 +42,4 @@ jobs:
         name: Validate
         uses: docker/bake-action@v3
         with:
-          targets: validate
+          targets: ${{ matrix.target }}