Log Message:
lang/ruby26-base: update to 2.6.7

Ruby 2.6.7 Released (2021-04-05)

This release includes security fixes.  Please check the topics below for
details.

* CVE-2020-25613: Potential HTTP Request Smuggling Vulnerability in
  WEBrick
* CVE-2021-28965: XML round-trip vulnerability in REXML

See the commit logs for details.

By this release, we end the normal maintenance phase of Ruby 2.6, and Ruby
2.6 enters the security maintenance phase.  This means that we will no
longer backport any bug fixes to Ruby 2.6 except security fixes.  The term
of the security maintenance phase is scheduled for a year.  Ruby 2.6 reaches
EOL and its official support ends by the end of the security maintenance
phase.  Therefore, we recommend that you start to plan upgrade to Ruby 2.7
or 3.0.