app, common: Remove duplicate directories from export functions

Both collect exports and flatpak_export_dir recursively export the
directories in their respective directory lists. Because of this,
including share/metainfo/releases when share/metainfo is already in the
lists is unnecessary and can cause exporting to fail because of
duplicate files.

app/flatpak-builtins-build-finish.c

@@ -239,7 +239,6 @@ collect_exports (GFile          *base,
     "share/krunner/dbusplugins",          /* KDE krunner DBus plugins */
     "share/appdata",                      /* Copy appdata/metainfo files (legacy path) */
     "share/metainfo",                     /* Copy appdata/metainfo files */
-    "share/metainfo/releases",            /* Copy AppStream release files */
     NULL,
   };
 

common/flatpak-dir.c

@@ -8997,7 +8997,6 @@ flatpak_export_dir (GFile        *source,
     "share/krunner/dbusplugins",           "../../..",
     "share/mime/packages",                 "../../..",
     "share/metainfo",                      "../..",
-    "share/metainfo/releases",             "../../..",
     "bin",                                 "..",
   };
   int i;