Disable sending performance traces to health.openneo.net

There's been some stability issues with our self-hosted
health.openneo.net service lately. I just upgraded to a new version
today, so my hope is that today's weird slowness is that it's doing the
expected GlitchTip 4.0 upgrade data migration process designed to save
disk space, and hopefully it will take care of itself by the end of the
day?

But just to help out, I'm disabling this feature to remove pressure on
the GlitchTip service. We don't actually use performance trace analysis
irl, and so it's just taking up disk space and processing power. If we
end up wanting to dig into something in the future, we can turn it back
on! (My hope had been that a sample rate of 5% was small enough to be a
good hedge to have "enough" data just in case something comes up, but
idk, I don't actually have a great sense of how much pressure even 5%
of our total volume is, and I'd rather just be certain it's out of the
picture altogether, at least while working on this.)

config/initializers/sentry.rb

@@ -1,5 +1,4 @@
 Sentry.init do |config|
   config.dsn = 'https://2d3c5b739af149a0b3beb86a4d498e1f@health.openneo.net/1'
   config.breadcrumbs_logger = [:active_support_logger, :http_logger]
-  config.traces_sample_rate = 0.05
 end