tests: drop 'compose' from the list of required tools for these tests, since it doesn't seem to be required

Signed-off-by: Mattia Rizzolo <mattia@debian.org>

Signed-off-by: Mattia Rizzolo <mattia@debian.org>

Gbp-Dch: ignore

Test case: diffoscope /usr/share/doc/libsane-common/canon/canon.changes /usr/share/doc/libsane-common/canon/canon.changes

Gbp-Dch: ignore

Avoid frequent long lines in RPM header outputs that cause very slow HTML output. (Closes: reproducible-builds/diffoscope#245)

In F-Droid, we use diffoscope in automated verification of APKs.  We need to
include the diffoscope config and version in a JSON report so that the
scheduler can know whether it needs to rerun diffoscope on a file. If the
diffoscope configuration or version has changed, then it should be run again.

Gbp-Dch: ignore

This turns the output in reproducible-builds/diffoscope#245 from 32MB ->
26MB uncompressed (although almost neglible gain when gzipped, of course).

Gbp-Dch: ignore

Actually don't emit "Unable to stat file" debug messages at all; we have entirely-artificial directory "entries" such as ELF sections which, of course, will never exist as files.

Don't emit a "Returning a FooContainer" - we already emit "Instantiating a FooContainer" log message.

Gbp-Dch: ignore

Don't call difflib.Differ.compare with very large inputs; it is at least O(n^2) and makes diffoscope (appear to) hang. (Closes: reproducible-builds/diffoscope#240)

Gbp-Dch: ignore

Gbp-Dch: ignore

Strip newlines when determining Black version to avoid "requires black >= 20.8b1 (18.9b0\n detected)" in test output.

Fix tempfile/weakref handling in Python 3.7 (ie. Debian buster). (Closes: reproducible-builds/diffoscope#239)

Gbp-Dch: ignore

Mark test_apk.py::test_android_manifest as being allowed to fail for now. (Re: reproducible-builds/diffoscope#237)