grafanaPlugins: prefer per-platform hashes to 'any'

Some packages have both per-platform _and_ an 'any' packages (e.g.
grafana-clickhouse-datasource) and the update script fails for those
cases. Prefer the per-platform packages if available.

pkgs/servers/monitoring/grafana/plugins/update-grafana-plugin.sh

@@ -35,8 +35,8 @@ update() {
     update-source-version $system "grafanaPlugins.${plugin_name}" "$latest_version" "$hash"
 }
 
-if echo "$api_response" | jq -e .packages.any > /dev/null; then
-    # the package contains an "any" package, so there should be only one zipHash.
+if echo "$api_response" | jq -e '.packages | select(length == 1) | .any' > /dev/null; then
+    # the package only contains an "any" package, so there should be only one zipHash.
     update "any"
 else
     update "linux-amd64" "x86_64-linux"