File fix-gschema.patch of Package tuner

diff -rubN tuner-2.0.3/data/meson.build tuner-2.0.3-patched/data/meson.build
--- tuner-2.0.3/data/meson.build	2026-03-09 18:41:55.000000000 +0100
+++ tuner-2.0.3-patched/data/meson.build	2026-03-17 12:26:42.157326240 +0100
@@ -95,6 +95,7 @@
 
 meson.add_install_script (
     glib_compile_schemas,
+    '--targetdir=' + meson.project_build_root(),
     schemas_dir,
     install_tag: 'schemas'
 )