librenms: add missing runtime dependencies

Adds packages required by LibreNMS features. They are currently configured in the librenms module,
but not available at runtime, causing some functionality to fail, e.g. graphs not rendered because
rrdtool is missing, or services not working because monitoring-plugins are not available.
This fixes the issue by adding the packages to buildInputs.

pkgs/servers/monitoring/librenms/default.nix

@@ -38,7 +38,18 @@ in phpPackage.buildComposerProject rec {
   php = phpPackage;
 
   buildInputs = [
+    graphviz
+    ipmitool
+    libvirt
+    monitoring-plugins
+    mtr
+    net-snmp
+    nfdump
+    nmap
+    rrdtool
+    system-sendmail
     unixtools.whereis
+    whois
     (python3.withPackages (ps: with ps; [
       pymysql
       python-dotenv