python: Fix .PHONY Make specifiers

python: Fix .PHONY Make specifiers

I missed the 'check-tox' target. Add that, but split the large .PHONY
specifier at the top into its component pieces and move them near the
targets they describe so that they're much harder to forget to update.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
Reviewed-by: Willian Rampazzo <willianr@redhat.com>
Message-id: 20210629214323.1329806-10-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>