Bump version after release (#4238)

Co-authored-by: GitHub <noreply@github.com>

Author: alexweininger

package-lock.json

@@ -2,7 +2,7 @@
     "name": "vscode-azurefunctions",
     "displayName": "Azure Functions",
     "description": "%azureFunctions.description%",
-    "version": "1.15.2",
+    "version": "1.15.2-alpha.1",
     "publisher": "ms-azuretools",
     "icon": "resources/azure-functions.png",
     "aiKey": "0c6ae279ed8443289764825290e4f9e2-1a736e7c-1324-4338-be46-fc2a58ae4d14-7255",