gnu: pbtranscript-tofu: Update to 2.2.3.

* gnu/packages/bioinformatics.scm (pbtranscript-tofu): Update to 2.2.3.
  [source]: Remove bundled Cython sources in a snippet.  Replace
  ".tar.gz" extension in file-name field with "-checkout".
  [arguments]: Replace "enter-directory-and-clean-up" phase with
  "enter-directory" phase, and add "patch-setuppy" phase.
  [inputs]: Add python2-h5py.  Move python2-cython ...
  [native-inputs]: ... to this field.