build: Make CD workflow only run after successful CI workflow

Co-authored-by: Sverre Nystad <89105607+SverreNystad@users.noreply.github.com>

.github/workflows/cd.yml

@@ -0,0 +1,21 @@
+name: CD
+
+on:
+  workflow_run:
+    workflows: ["CI"]  
+    types:
+      - completed
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    # Only runs if CI was successful
+    if: ${{ github.event.workflow_run.conclusion == 'success' }}  
+    steps:
+      - uses: actions/checkout@v4
+      - name: Build the Docker image
+        run: docker build . --file Dockerfile --tag ntnu-kpro-ai-assistant:$(date +%s)
+
+      - name: Push the Docker image
+        run: echo TODO Push the Docker image