Generate absolute paths for Gitaly test config files

Previously the GitLab tests generated TOML files with relative paths,
but due to some change in Gitaly
(https://gitlab.com/gitlab-org/gitaly/-/issues/3436) these relative
paths no longer work.

We now use an absolute path to ensure that the tests continue to work.

lib/gitlab/setup_helper.rb

@@ -121,7 +121,7 @@ module Gitlab
 
           config[:'gitaly-ruby'] = { dir: File.join(gitaly_dir, 'ruby') } if gitaly_ruby
           config[:'gitlab-shell'] = { dir: Gitlab.config.gitlab_shell.path }
-          config[:bin_dir] = Gitlab.config.gitaly.client_path
+          config[:bin_dir] = File.expand_path(Gitlab.config.gitaly.client_path)
           config[:gitlab] = { url: Gitlab.config.gitlab.url }
           config[:logging] = { dir: Rails.root.join('log').to_s }
 

spec/support/helpers/test_env.rb

@@ -184,7 +184,7 @@ module TestEnv
   end
 
   def gitaly_dir
-    File.dirname(gitaly_socket_path)
+    File.dirname(File.expand_path(gitaly_socket_path))
   end
 
   def start_gitaly(gitaly_dir)