ci: use ddk for faster ci, manual gki image build

Co-authored-by: Ylarod <me@ylarod.cn>

kernel/.vscode/tasks.json

@@ -0,0 +1,16 @@
+{
+    // See https://go.microsoft.com/fwlink/?LinkId=733558
+    // for the documentation about the tasks.json format
+    "version": "2.0.0",
+    "tasks": [
+        {
+            "label": "Generate compile_commands.json",
+            "type": "process",
+            "command": "python",
+            "args": [
+                "${workspaceRoot}/.vscode/generate_compdb.py"
+            ],
+            "problemMatcher": []
+        }
+    ]
+}