Update the Iris color picker to version 1.0.7.

Includes a fix for multiple pickers on the same page.
Changes: https://github.com/Automattic/Iris/compare/1.0.6...1.0.7

props mattwiebe.
fixes #30537.

git-svn-id: https://develop.svn.wordpress.org/trunk@30650 602fd350-edb4-49c9-b593-d223f7449a82