Rename deprecated normalize to unicode_normalize

This merge request introduces the following changes:

- uses unicode_normalize instead of the deprecated normalize
- updates babosa gem the new version that fixes the warning

Gemfile

@@ -267,7 +267,7 @@ gem 'kubeclient', '~> 4.9.1'
 
 # Sanitize user input
 gem 'sanitize', '~> 5.2.1'
-gem 'babosa', '~> 1.0.2'
+gem 'babosa', '~> 1.0.4'
 
 # Sanitizes SVG input
 gem 'loofah', '~> 2.2'

Gemfile.lock

@@ -132,7 +132,7 @@ GEM
       faraday_middleware (~> 1.0.0.rc1)
       net-http-persistent (~> 4.0)
       nokogiri (~> 1.11.0.rc2)
-    babosa (1.0.2)
+    babosa (1.0.4)
     backport (1.1.2)
     base32 (0.3.2)
     batch-loader (2.0.1)
@@ -1378,7 +1378,7 @@ DEPENDENCIES
   aws-sdk-cloudformation (~> 1)
   aws-sdk-core (~> 3)
   aws-sdk-s3 (~> 1)
-  babosa (~> 1.0.2)
+  babosa (~> 1.0.4)
   base32 (~> 0.3.0)
   batch-loader (~> 2.0.1)
   bcrypt (~> 3.1, >= 3.1.14)

lib/gitlab/auth/o_auth/auth_hash.rb

@@ -81,7 +81,7 @@ module Gitlab
         # Get the first part of the email address (before @)
         # In addition in removes illegal characters
         def generate_username(email)
-          email.match(/^[^@]*/)[0].mb_chars.normalize(:kd).gsub(/[^\x00-\x7F]/, '').to_s
+          email.match(/^[^@]*/)[0].mb_chars.unicode_normalize(:nfkd).gsub(/[^\x00-\x7F]/, '').to_s
         end
 
         def generate_temporarily_email(username)