debug: improve self-host debug configurations

https://github.com/microsoft/vscode/issues/100368

.vscode/launch.json

@@ -226,7 +226,9 @@
 				"--no-cached-data",
 			],
 			"webRoot": "${workspaceFolder}",
-			// Settings for js-debug:
+			"cascadeTerminateToConfigurations": [
+				"Attach to Extension Host"
+			],
 			"userDataDir": false,
 			"pauseForSourceMap": false,
 			"outFiles": [
@@ -436,6 +438,7 @@
 				"Attach to Extension Host",
 				"Attach to Shared Process",
 			],
+			"preLaunchTask": "Ensure Prelaunch Dependencies",
 			"presentation": {
 				"group": "0_vscode",
 				"order": 1