Fix Debian build by using correct register-python-argcomplete

Debian does not seem to have a command `python3-argcomplete3` anymore.
Instead the command is nowadays without the `3`, see
https://packages.debian.org/search?mode=path&suite=bookworm&section=all&arch=any&searchon=contents&keywords=register-python-argcomplete

Author: ottok

debian/rules

@@ -17,6 +17,6 @@ override_dh_auto_build:
 		--name="Check all of the things!" \
 		./$P \
 		> $P.1
-	register-python-argcomplete3 check-all-the-things > debian/$P.bash-completion
+	register-python-argcomplete check-all-the-things > debian/$P.bash-completion
 	sed -i s/_python_argcomplete/_check_all_the_things_argcomplete/ debian/$P.bash-completion
 	sed -i 's/$$1/check-all-the-things/' debian/$P.bash-completion