The default limit (at least on Linux) causes us to run out of file
descriptors at around 15 tabs. Increase this limit to 8k. This is a
rather arbitrary number, but matches the limit set by Chrome.
(cherry picked from commit d58a8b514647a1137d76a1d601f0c325a51f29b3;
amended to also update Userland/Applications/Browser/main.cpp)