test_diff_consistency and test_benchmark_diff both read an uncompressed
test/dumps/ikwiki.xml that is not in the repository, so enabling them
requires decompressing the .bz2 first; test_diff_consistency also
writes debug files to the current directory. Say so where the skip
markers are.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
(cherry picked from commit fde1452666)