CI: test dmd and ldc2 on ubuntu macos and windows

Signed-off-by: Andrei Horodniceanu <a.horodniceanu@proton.me>

Author: the-horo

.github/workflows/d.yml

@@ -15,12 +15,16 @@ permissions:
 
 jobs:
   build:
-
-    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        os: [ubuntu-latest, macos-latest, windows-latest]
+        dc: [dmd, ldc]
+    runs-on: ${{ matrix.os }}
 
     steps:
     - uses: actions/checkout@v4
     - uses: dlang-community/setup-dlang@v2
+      with: ${{ matrix.dc }}
 
     - name: 'Build & Test'
       run: |