Don't allow spaces in dependency linker value regex

lib/gitlab/dependency_linker/base_linker.rb

 module Gitlab
   module DependencyLinker
     class BaseLinker
-      URL_REGEX = %r{https?://[^'"]+}.freeze
-      REPO_REGEX = %r{[^/'"]+/[^/'"]+}.freeze
+      URL_REGEX = %r{https?://[^'" ]+}.freeze
+      REPO_REGEX = %r{[^/'" ]+/[^/'" ]+}.freeze
 
       class_attribute :file_type
 
@@ -69,7 +69,7 @@ module Gitlab
         @highlighted_lines ||= highlighted_text.lines
       end
 
-      def regexp_for_value(value, default: /[^'"]+/)
+      def regexp_for_value(value, default: /[^'" ]+/)
         case value
         when Array
           Regexp.union(value.map { |v| regexp_for_value(v, default: default) })

lib/gitlab/dependency_linker/json_linker.rb

@@ -24,8 +24,8 @@ module Gitlab
       #   link_json('specific_package', '1.0.1', link: :key)
       #   # Will link `specific_package` in `"specific_package": "1.0.1"`
       def link_json(key, value = nil, link: :value, &url_proc)
-        key = regexp_for_value(key, default: /[^"]+/)
-        value = regexp_for_value(value, default: /[^"]+/)
+        key = regexp_for_value(key, default: /[^" ]+/)
+        value = regexp_for_value(value, default: /[^" ]+/)
 
         if link == :value
           value = /(?<name>#{value})/