meson: Update meson minimum version to 0.56.0

The following warnings were generated:

     bundle/meson.build:19: WARNING: Project targets '>= 0.49.0' but uses
     feature introduced in '0.50.0': install arg in configure_file.

    WARNING: Project specifies a minimum meson_version '>= 0.49.0' but
    uses features which were added in newer versions:
     * 0.50.0: {'install arg in configure_file'}
    NOTICE: Future-deprecated features used:
     * 0.55.0: {'ExternalProgram.path'}
     * 0.56.0: {'meson.source_root', 'meson.build_root'}

However, after updating new warnings were generated:

    WARNING: Deprecated features used:
     * 0.55.0: {'ExternalProgram.path'}
     * 0.56.0: {'meson.build_root', 'meson.source_root'}

Update meson minimum version to 0.56.0 and fix the generated warnings.

bundle/meson.build

@@ -4,7 +4,7 @@ gnome = import('gnome')
 message('Building the application entry point: ' + join_paths(get_option('bindir'), meson.project_name()))
 
 bin_conf = configuration_data()
-bin_conf.set('GJS', gjs_bin.path())
+bin_conf.set('GJS', gjs_bin.full_path())
 bin_conf.set('PACKAGE_VERSION', meson.project_version())
 bin_conf.set('PROJECT_NAME', meson.project_name())
 bin_conf.set('prefix', get_option('prefix'))
@@ -29,9 +29,9 @@ app_bundle = custom_target(
   build_always_stale: true,
   command: [
     node_bin,
-    join_paths(meson.source_root(), 'bundle', 'scripts', 'build.js'),
-    meson.source_root(),
-    join_paths(meson.build_root(), '@OUTDIR@'),
+    join_paths(meson.project_source_root(), 'bundle', 'scripts', 'build.js'),
+    meson.project_source_root(),
+    join_paths(meson.project_build_root(), '@OUTDIR@'),
     get_option('buildtype'),
     meson.project_name(),
     get_option('flatpak'),

meson.build

@@ -2,7 +2,7 @@ project(
   'com.github.joseexposito.touche',
   version: '2.0.9',
   license: 'GPL-3.0-or-later',
-  meson_version: '>= 0.49.0',
+  meson_version: '>= 0.56.0',
   default_options: [ 'warning_level=2' ],
 )
 

subprojects/libtouche/meson.build

@@ -2,7 +2,7 @@ project(
   'libtouche',
   'cpp',
   version: '2.0.0', # Warning: If you increase this version remember to change src/pkg-init.js
-  meson_version: '>= 0.49.0'
+  meson_version: '>= 0.56.0'
 )
 
 gnome = import('gnome')