[gegl] Revert "meson: use python installation found by meson"

[Øyvind "pippin" Kolås <ok src gnome org>]

commit ad7021110c9c6717fa0d783355e4924cc354a0ee
Author: Øyvind Kolås <pippin gimp org>
Date:   Fri Aug 16 02:29:36 2019 +0200

    Revert "meson: use python installation found by meson"
    
    This reverts commit ccd6279f4a4a742e72c55931c831fd5da3592fc4.
    gitlab CI on gitlab.gnome.org passed, but gnome continuous and
    other reported systems fail with this change see:
    
    http://build.gnome.org/continuous/buildmaster/builds/2019/08/15/37/build/log-gegl.txt

 opencl/meson.build             | 2 +-
 tests/compositions/meson.build | 2 +-
 tests/python/meson.build       | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/opencl/meson.build b/opencl/meson.build
index e00b860d4..6c5bee0a2 100644
--- a/opencl/meson.build
+++ b/opencl/meson.build
@@ -56,6 +56,6 @@ foreach source : opencl_sources
   opencl_headers += custom_target(source + '.h',
     input : source,
     output: source +'.h',
-    command: [ python, cltostring, '@INPUT@', '@OUTPUT@' ],
+    command: [ cltostring, '@INPUT@', '@OUTPUT@' ],
   )
 endforeach
diff --git a/tests/compositions/meson.build b/tests/compositions/meson.build
index b30955d9a..268eda4ec 100644
--- a/tests/compositions/meson.build
+++ b/tests/compositions/meson.build
@@ -73,7 +73,7 @@ run_compositions = find_program('run-compositions.py')
 
 if false
 test('compositions_with_opencl',
-  [ python, run_compositions ],
+  run_compositions,
   args: [
     '--build-dir='+ meson.build_root(),
     '--src-dir='  + meson.source_root(),
diff --git a/tests/python/meson.build b/tests/python/meson.build
index c92f8a4a3..f0f9c5868 100644
--- a/tests/python/meson.build
+++ b/tests/python/meson.build
@@ -11,7 +11,7 @@ if python.found() and pygobject_found
   foreach testname : testnames
     testfile = 'test-' + testname + '.py'
     test(testname,
-      [ python, find_program(testfile) ],
+      find_program(testfile),
       env: [
         'LD_LIBRARY_PATH=' + meson.build_root() / 'gegl' + ':$LD_LIBRARY_PATH',
         'GI_TYPELIB_PATH=' + meson.build_root() / 'gegl' + ':$GI_TYPELIB_PATH',