feat: change qdisc to fq_codel for modern Linux kernels

Signed-off-by: k4yt3x <i@k4yt3x.com>

Author: k4yt3x

sysctl.conf

@@ -8,7 +8,7 @@
 
 # Licensed under the GNU General Public License Version 3 (GNU GPL v3),
 #   available at: https://www.gnu.org/licenses/gpl-3.0.txt
-# (C) 2020-2025 K4YT3X
+# Copyright 2020-2025 K4YT3X and contributors.
 
 # Multiple sources have been consulted while writing this configuration
 #   file (e.g., nixCraft's sysctl.conf). Some sources may not have been cited.
@@ -166,9 +166,9 @@ net.core.optmem_max = 40960
 
 ########## IPv4 Networking ##########
 
-# enable BBR congestion control
+# enable BBR congestion control and FQ-CoDel queuing discipline
 net.ipv4.tcp_congestion_control = bbr
-net.core.default_qdisc = fq
+net.core.default_qdisc = fq_codel
 
 # disallow IPv4 packet forwarding
 net.ipv4.ip_forward = 0