Updating Gemfile.lock for rubocop-rspec dependecy.

GDK pipeline is failing with this error:
```
Downloading rubocop-rspec-1.15.1 revealed dependencies not in the API or the
lockfile (rubocop (>= 0.42.0)).
Either installing with `--full-index` or running `bundle update rubocop-rspec`
should fix the problem.
```
Updated lockfile by running the bundle update.

`gdk install` works now.

Gemfile.lock

@@ -744,6 +744,7 @@ GEM
     rubocop-gitlab-security (0.0.6)
       rubocop (>= 0.47.1)
     rubocop-rspec (1.15.1)
+      rubocop (>= 0.42.0)
     ruby-fogbugz (0.2.1)
       crack (~> 0.4)
     ruby-prof (0.16.2)