Hi. Thanks for the report.
The easiest solution is probably to add option "--output=$(package)" to the makeinfo --html in d/rules, but this needs to be verified.
I confirm that adding --output=$(package) works (and also produces identical results in unstable according to diffoscope). BTW: The new Texinfo package now depends on install-info. Is that normal/expected?
after bookworm we'll upload TeXInfo 7.0 to unstable and the bug will become RC.
Hopefully that will not be necessary, because there was another simple bug in m4 to fix (the one about loongarch), so I've decided to make an upload to fix both. Thanks.