Bump newrelic_rpm from 8.3.0 to 8.4.0

Bumps [newrelic_rpm](https://github.com/newrelic/newrelic-ruby-agent) from 8.3.0 to 8.4.0.
- [Release notes](https://github.com/newrelic/newrelic-ruby-agent/releases)
- [Changelog](https://github.com/newrelic/newrelic-ruby-agent/blob/dev/CHANGELOG.md)
- [Commits](https://github.com/newrelic/newrelic-ruby-agent/compare/8.3.0...8.4.0)

---
updated-dependencies:
- dependency-name: newrelic_rpm
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Gemfile.lock

@@ -288,7 +288,7 @@ GEM
     net-http-persistent (4.0.1)
       connection_pool (~> 2.2)
     netrc (0.11.0)
-    newrelic_rpm (8.3.0)
+    newrelic_rpm (8.4.0)
     nio4r (2.5.8)
     nokogiri (1.11.7)
       mini_portile2 (~> 2.5.0)