meson: Fix checking for python

When running with -Dpython-checks=false, the build fails. To fix this,
we move the python variable declaration outside of the get_option()
block as it will be used for calling the generators. Also removes the
unnecessary check for python3-devel.

Signed-off-by: Eduardo Lima (Etrunko) <etrunko@redhat.com>
Acked-by: Frediano Ziglio <fziglio@redhat.com>

.gitlab-ci.yml

@@ -4,7 +4,7 @@ before_script:
   - >
     dnf install 'dnf-command(copr)' git libtool make libasan
     python3 python3-six python3-pyparsing glib-networking
-    python3-devel meson ninja-build gdk-pixbuf2-devel
+    meson ninja-build gdk-pixbuf2-devel
     -y
   - dnf copr enable @spice/nightly -y
   - dnf builddep spice -y

meson.build

@@ -128,11 +128,12 @@ foreach dep : optional_deps
 endforeach
 
 # Python
+py_module = import('python3')
+python = py_module.find_python()
+
 if get_option('python-checks')
-  dependency('python3')
-  py_module = import('python3')
-  python = py_module.find_python()
   foreach module : ['six', 'pyparsing']
+    message('Checking for python module @0@'.format(module))
     cmd = run_command(python, '-m', module)
     if cmd.returncode() != 0
       error('Python module @0@ not found'.format(module))