build-sys: Stop checking for Python

We don't need it anymore at build time.  The test suite
still uses it, but we detect it dynamically there.

Closes: #1505
Approved by: jlebon

configure.ac

@@ -117,23 +117,6 @@ AS_IF([pkg-config --atleast-version=4.14.2-rc1 rpm], [
 
 AC_PATH_PROG([XSLTPROC], [xsltproc])
 
-dnl This was painful to figure out; it's sad that Automake's
-dnl python support doesn't do a better job of optionally supporting
-dnl both 2 and 3.  Anyways the logic here is: Honor $PYTHON if set
-dnl uncondionally, otherwise try python3 if it appears to be available
-dnl first, then fall back to 2.
-dnl Recommendation is explicit PYTHON=python3 ./configure ...
-AS_IF([test -z "$PYTHON"], [
-  AS_IF([test -x /usr/bin/python3], [
-    AM_PATH_PYTHON([3.6])
-  ], [
-    AM_PATH_PYTHON([2.7])
-  ])
-])
-dnl http://maemo.org/maemo_training_material/maemo4.x/html/maemo_Application_Development_Chinook/Chapter_05_GNU_Autotools.html
-dnl incorrectly says the quoted ']' is @>:@ (...crying...)
-pyver=$($PYTHON -c "import sys; sys.stdout.write(sys.version @<:@ :3 @:>@ )")
-
 GLIB_TESTS
 LIBGLNX_CONFIGURE
 
@@ -247,12 +230,6 @@ else
   export cmake_args
 fi
 
-case "${pyver}" in
-  2.*) cmake_args="${cmake_args} -DPYTHON_DESIRED:str=2";;
-  3.*) cmake_args="${cmake_args} -DPYTHON_DESIRED:str=3";;
-  *) AC_MSG_ERROR([unexpected \$pyver $pyver]);;
-esac
-
 dnl I picked /usr/libexec/rpm-ostree just because we need an
 dnl arbitrary path - we don't actually install there.
 (set -euo pipefail; mkdir -p libdnf-build && cd libdnf-build &&
@@ -287,6 +264,5 @@ echo "
     introspection:                           $found_introspection
     bubblewrap:                              $with_bubblewrap
     gtk-doc:                                 $enable_gtk_doc
-    python:                                  $PYTHON $pyver
     rust:                                    $enable_rust
 "