Comment # 1 on bug 1186711 from Christian Boltz

The last big(ger) change was the update to AppArmor 3.0.1 - but that was
already on Dec 02 2020. Since then, there were a few small patches added (all
adding more permissions) and a few small packaging changes - nothing that could
explain your dnsmasq problems.

What's the previous rule you had to allow running your script?
(The shipped dnsmasq profile never allowed to run anything in /usr/local/, so
if your answer is "no previous rule", then please check your logs if that
"failed to execute" message is really new.)