Alternate name for dumppdf tool

Guix includes the python-pdfminer-six package, which includes a "dumppdf.py" script which appears to be from the same upstream as Debian's python3-pdfminer package, which ships it as "dumppdf". I suspect upstream actually ships this as "dumppdf.py" too...

It seems like the ideal approach would be to support the tool as either name, though it wasn't obvious to me if that should involve conditional logic in tool_requires to support either, or allow tool_requires to take either of N arguments as a tool, or what should be listed in external_tools.py (e.g. one entry with for "dumppdf" and one for "dumppdf.py"? assume without the .py extension but optionally add it?)

Workarounds for guix are pretty simple; patch diffoscope to use dumppdf.py instead, or to add symlinks in the python-pdfminer-six package so that either work... but this would have to be done in each distribution that has dumppdf.py rather than dumppdf.