Properly handle colons in URL passwords

Before b46d5b13, we relied on
`Addressable::URI` to parse the username/password in a URL, but this failed
when credentials contained special characters. However, this introduced a regression
where the parsing would incorrectly truncate the password if the password had a colon.

Closes #49080

changelogs/unreleased/sh-handle-colons-in-url-passwords.yml

+---
+title: Properly handle colons in URL passwords
+merge_request:
+author:
+type: fixed

lib/gitlab/url_sanitizer.rb

@@ -58,7 +58,7 @@ module Gitlab
       if raw_credentials.present?
         url.sub!("#{raw_credentials}@", '')
-        user, password = raw_credentials.split(':')
+        user, _, password = raw_credentials.partition(':')
         @credentials ||= { user: user.presence, password: password.presence }
       end

spec/lib/gitlab/url_sanitizer_spec.rb

@@ -92,6 +92,7 @@ describe Gitlab::UrlSanitizer do
     context 'credentials in URL' do
       where(:url, :credentials) do
         'http://foo:bar@example.com' | { user: 'foo', password: 'bar' }
+        'http://foo:bar:baz@example.com' | { user: 'foo', password: 'bar:baz' }
         'http://:bar@example.com'    | { user: nil,   password: 'bar' }
         'http://foo:@example.com'    | { user: 'foo', password: nil }
         'http://foo@example.com'     | { user: 'foo', password: nil }