[gimp] pdb, po-tips: fix meson warnings.

[Jehan <jehanp src gnome org>]

commit c857fc58a6b9f9030a240c8ba85545f32756bc7e
Author: Jehan <jehan girinstud io>
Date:   Sun Jul 31 17:40:39 2022 +0200

    pdb, po-tips: fix meson warnings.
    
    Meson is apparently able to show different warning depending on the
    meson version tests we do in specific code paths.
    
    Since our global required meson is 0.53.0 but on some code paths, we
    test for 0.57.0, we must use meson.source_root() on older meson and
    meson.project_source_root() on newer one.
    
    Fixes:
    
    > pdb/meson.build:141: WARNING: Project targets '>=0.57.0' but uses feature deprecated since '0.56.0': 
meson.source_root. use meson.project_source_root() or meson.global_source_root() instead.
    > pdb/meson.build:141: WARNING: Project targets '>=0.57.0' but uses feature deprecated since '0.56.0': 
meson.build_root. use meson.project_build_root() or meson.global_build_root() instead.
    > po-tips/meson.build:5: WARNING: Project targets '>=0.53.0' but uses feature introduced in '0.56.0': 
meson.project_source_root.

 pdb/meson.build     | 2 +-
 po-tips/meson.build | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/pdb/meson.build b/pdb/meson.build
index 66997ae21b..1df5897bfd 100644
--- a/pdb/meson.build
+++ b/pdb/meson.build
@@ -138,7 +138,7 @@ if meson.version().version_compare('>=0.57.0')
     output: [ 'stamp-pdbgen.h', ],
     env: perl_env,
     command: [
-      pdbgen_run, perl, meson.source_root(), meson.build_root()
+      pdbgen_run, perl, meson.project_source_root(), meson.project_build_root()
     ],
   )
 
diff --git a/po-tips/meson.build b/po-tips/meson.build
index e0e1fd34ef..c9a9e30bef 100644
--- a/po-tips/meson.build
+++ b/po-tips/meson.build
@@ -2,5 +2,5 @@ potips_dir = meson.current_source_dir()
 i18n.gettext(gettext_package + '-tips',
   preset: 'glib',
   install: false,
-  data_dirs: meson.project_source_root() / 'data' / 'tips',
+  data_dirs: meson.source_root() / 'data' / 'tips',
 )