build(deps): bump newrelic_rpm from 6.12.0.367 to 6.13.1

Bumps [newrelic_rpm](https://github.com/newrelic/newrelic-ruby-agent) from 6.12.0.367 to 6.13.1.
- [Release notes](https://github.com/newrelic/newrelic-ruby-agent/releases)
- [Changelog](https://github.com/newrelic/newrelic-ruby-agent/blob/dev/CHANGELOG.md)
- [Commits](newrelic/newrelic-ruby-agent@6.12.0.367...6.13.1)

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

Author: dependabot[bot]

Gemfile.lock

@@ -297,7 +297,7 @@ GEM
     net-ssh (6.1.0)
     netaddr (2.0.4)
     netrc (0.11.0)
-    newrelic_rpm (6.12.0.367)
+    newrelic_rpm (6.13.1)
     nokogiri (1.10.10)
       mini_portile2 (~> 2.4.0)
     os (1.0.1)