Disable the fetchClosure test for old daemons

Broken because of the change introduced by #4282

tests/fetchClosure.sh

@@ -5,6 +5,12 @@ enableFeatures "fetch-closure"
 clearStore
 clearCacheCache
 
+# Old daemons don't properly zero out the self-references when
+# calculating the CA hashes, so this breaks `nix store
+# make-content-addressed` which expects the client and the daemon to
+# compute the same hash
+requireDaemonNewerThan "2.16.0pre20230524"
+
 # Initialize binary cache.
 nonCaPath=$(nix build --json --file ./dependencies.nix --no-link | jq -r .[].outputs.out)
 caPath=$(nix store make-content-addressed --json $nonCaPath | jq -r '.rewrites | map(.) | .[]')