gnu: glib: Update to 2.37.1.

* gnu/packages/glib.scm (glib): Update to 2.37.1.  Add Bash and tzdata
  as inputs.  Remove `glib-tests-timezone.patch'.  Augment `pre-build'
  phase to set `TZDIR', `XDG_CACHE_HOME', and to modify makefiles to
  honor $(TESTS_ENVIRONMENT).
* gnu/packages/patches/glib-tests-desktop.patch,
  gnu/packages/patches/glib-tests-homedir.patch: Update.
* gnu/packages/patches/glib-tests-timezone.patch: Remove.
* Makefile.am (dist_patch_DATA): Update accordingly.

distro: glib: Run the test suite; add DBus.

* distro/packages/glib.scm: Rename to...
* gnu/packages/glib.scm: ... this.  Update module declaration
  accordingly.
  (dbus): New variable.
  (glib): Change version number to 2.34.3, and adjust URL accordingly.
  Add a "doc" output.  Add #:configure-flags, #:patches, and #:phases
  arguments. Add DBUS as an input, as well a three patches.
* Makefile.am (MODULES): Adjust to file renaming.
  (dist_patch_DATA): Add `glib-tests-timezone.patch',
  `glib-tests-homedir.patch', and `glib-tests-desktop.patch'.