build: create check for python black

If python black is install then it would check the
formating of all of the python files and test the for it.
Otherwise, it would just simply ignore the python black
if python black is not installed.

Makefile.am

@@ -5235,6 +5235,11 @@ CLEANFILES += \
 ###############################################################################
 
 include Makefile.examples
+if WITH_PYTHON_BLACK
+check-python-black:
+	$(BLACK) --check $(top_srcdir)
+check_local += check-python-black
+endif
 
 ###############################################################################
 

configure.ac

@@ -1272,6 +1272,10 @@ else
 	have_introspection=no
 fi
 
+# check for python black. And check if all files are formatted with python black
+AC_PATH_PROG(BLACK, black)
+AM_CONDITIONAL(WITH_PYTHON_BLACK, test "${BLACK}" != "")
+
 # check for pregenerated manpages and documentation to be installed
 use_pregen_docs=no
 if test "$build_docs" != "yes" -a \