Log Message:
ruby-nokogiri: update to 1.12.4.

Upstream changes
https://github.com/sparklemotion/nokogiri/releases/tag/v1.12.4

1.12.4 / 2021-08-29

Notable fix: Namespace inheritance

Namespace behavior when reparenting nodes has historically been poorly
specified and the behavior diverged between CRuby and JRuby. As a result,
making this behavior consistent in v1.12.0 introduced a breaking change.

This patch release reverts the Builder behavior present in v1.12.0..v1.12.3 but
keeps the Document behavior. This release also introduces a Document attribute
to allow affected users to easily change this behavior for their legacy code
without invasive changes.

Compensating Feature in XML::Document

This release of Nokogiri introduces a new Document boolean attribute,
namespace_inheritance, which controls whether children should inherit a
namespace when they are reparented. Nokogiri::XML:Document defaults this
attribute to false meaning "do not inherit," thereby making explicit the
behavior change introduced in v1.12.0.

CRuby users who desire the pre-v1.12.0 behavior may set
document.namespace_inheritance = true before reparenting nodes.

See https://nokogiri.org/rdoc/Nokogiri/XML/Document.html#
namespace_inheritance-instance_method for example usage.

Fix for XML::Builder

However, recognizing that we want Builder-created children to inherit
namespaces, Builder now will set namespace_inheritance=true on the underlying
document for both JRuby and CRuby. This means that, on CRuby, the pre-v1.12.0
behavior is restored.

Users who want to turn this behavior off may pass a keyword argument to the
Builder constructor like so:

Nokogiri::XML::Builder.new(namespace_inheritance: false)

See https://nokogiri.org/rdoc/Nokogiri/XML/Builder.html#
label-Namespace+inheritance for example usage.

Downstream gem maintainers

Note that any downstream gems may want to specifically omit Nokogiri
v1.12.0--v1.12.3 from their dependency specification if they rely on child
namespace inheritance:

Gem::Specification.new do |gem|
  # ...
  gem.add_runtime_dependency 'nokogiri', '!=1.12.3', '!=1.12.2', '!=1.12.1', \ 
'!=1.12.0'
  # ...
end

Fixed

  * [JRuby] Fix NPE in Schema parsing when an imported resource doesn't have a
    systemId. [#2296] (Thanks, @pepijnve!)