Bump bugsnag from 6.21.0 to 6.26.0 in /lib/nexmo_developer

Bumps [bugsnag](https://github.com/bugsnag/bugsnag-ruby) from 6.21.0 to 6.26.0.
- [Release notes](https://github.com/bugsnag/bugsnag-ruby/releases)
- [Changelog](https://github.com/bugsnag/bugsnag-ruby/blob/master/CHANGELOG.md)
- [Commits](https://github.com/bugsnag/bugsnag-ruby/commits)

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

Signed-off-by: dependabot[bot] <[email protected]>

lib/nexmo_developer/Gemfile.lock

@@ -111,7 +111,7 @@ GEM
       debug_inspector (>= 0.0.1)
     bootsnap (1.7.5)
       msgpack (~> 1.0)
-    bugsnag (6.21.0)
+    bugsnag (6.26.0)
       concurrent-ruby (~> 1.0)
     builder (3.2.4)
     byebug (11.1.3)
@@ -133,7 +133,7 @@ GEM
       execjs
     coffee-script-source (1.12.2)
     colorize (0.8.1)
-    concurrent-ruby (1.1.10)
+    concurrent-ruby (1.2.2)
     countries (3.1.0)
       i18n_data (~> 0.11.0)
       sixarm_ruby_unaccent (~> 1.1)