Use installer list in dynamic matrix

.github/workflows/test_changes.yml

@@ -4,8 +4,8 @@ on:
   workflow_dispatch:
 
 jobs:
-  list_changes:
-    name: List changed installers
+  list_installers:
+    name: List installers under test
     runs-on: ubuntu-latest
     outputs:
       installers: ${{ github.event_name == 'push' && steps.changed.outputs.changed_installers || steps.all.outputs.all_installers }}
@@ -49,3 +49,31 @@ jobs:
         run: |
           echo "$EVENT_NAME"
           echo "$EVENT"
+
+  test_installers:
+    name: Test installers
+    needs: list_installers
+    runs-on: ubuntu-latest
+    container:
+      image: ${{matrix.os}}
+    strategy:
+      fail-fast: false
+      matrix:
+        installer: ${{ fromJson(needs.list_installers.outputs.installers) }}
+        os: ["ubuntu:20.04", "ubuntu:22.04"]
+    steps:
+      - name: Check out code
+        uses: actions/checkout@v4
+
+      - name: Prepare Docker
+        run: ./scripts/prepare_docker.bash
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Install ${{matrix.installer}}
+        shell: su norm --command "bash --login {0}"
+        run: programs/${{matrix.installer}}/install.bash
+
+      - name: Install ${{matrix.installer}} again (test idempotency)
+        shell: su norm --command "bash --login {0}"
+        run: programs/${{matrix.installer}}/install.bash