An old snippet was causing the build to fail when using Emacs 27.
* gnu/packages/emacs-xyz.scm (emacs-yasnippet)[source]: Use git-file-name, and
remove obsolete snippet.
[phases]{home}: New phase. This allows the rebindings test to pass.
{make-tests-writable, delete-rebinding-test}: Remove phases.
[description]: Re-indent.
fb8542ed5c