Expand declarative upstream providers

pkgbuilds/tzupdate/.omarchy/package.json

@@ -1,3 +1,10 @@
 {
-  "source": "local"
+  "source": "local",
+  "upstream": {
+    "git_tags": "https://github.com/cdown/tzupdate.git",
+    "tag_pattern": "{pkgver}",
+    "sources": {
+      "any": ["https://github.com/cdown/tzupdate/archive/refs/tags/{tag}.tar.gz"]
+    }
+  }
 }