backend: refactor server/nodeinfo.ts

This fixes a few type errors like removing `software.respository` in
NodeInfo 2.0 and updating `metadata.repositoryUrl` to not use the
now removed meta `repositoryUrl` field.

@@ -83,3 +110,3 @@
 };
 
-const cache = new Cache<Awaited<ReturnType<typeof nodeinfo2>>>(1000 * 60 * 10);
+const cache = new Cache<NodeInfo2Base>(10 * MINUTE);