Replace strange $TEST_FUNCTIONS variable/expansion thing with
something more like what we use in nbdkit, a simple tests/functions.sh
script that gets sourced into each test script.
Update the common submodule to get:
commit 8137d47d0e654065391151eb275e3b64f230f6f5
Author: Richard W.M. Jones <rjones@redhat.com>
Date: Thu Feb 13 11:13:55 2025 +0000
mlcustomize, mltools: Replace $TEST_FUNCTIONS
TEST_FUNCTIONS is being removed from libguestfs and guestfs-tools (it
was removed from virt-v2v a while back). Make the same adjustment in
the common submodule.
(and some other commits which are not relevant to libguestfs)
Apply this change across all the shell scripts containing tests.
Additionally this defines the environment variables $abs_srcdir,
$abs_builddir, $top_srcdir, $top_builddir, $abs_top_srcdir and
$abs_top_builddir which can now be used throughout test scripts.
