package/libostree: needs headers >= 5.4

linux/fsverity.h is only available since kernel 5.4 and
https://github.com/torvalds/linux/commit/085771ec14b9bdb843fe9283d4703ced395d1b0b
resulting in the following build failure since bump to version 2023.5 in
commit c64a3e9767757f6bab0ecf2df35871508003f39e and
https://github.com/containers/composefs/commit/d3b4b1a2599e74757a3ada47a88645b363067a0a:

composefs/libcomposefs/lcfs-writer-erofs.c:37:10: fatal error: linux/fsverity.h: No such file or directory
   37 | #include <linux/fsverity.h>
      |          ^~~~~~~~~~~~~~~~~~

Fixes:
 - http://autobuild.buildroot.org/results/045987a09cf9061dae80db6ada1f912b2867db26

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>

package/libostree/Config.in

@@ -6,6 +6,7 @@ config BR2_PACKAGE_LIBOSTREE
 	depends on BR2_USE_MMU # e2fsprogs, libglib2, libgpgme
 	# doesn't build with musl due to lack of TEMP_FAILURE_RETRY()
 	depends on !BR2_TOOLCHAIN_USES_MUSL
+	depends on BR2_TOOLCHAIN_HEADERS_AT_LEAST_5_4 # linux/fsverity.h
 	select BR2_PACKAGE_E2FSPROGS
 	select BR2_PACKAGE_LIBARCHIVE if BR2_s390x
 	select BR2_PACKAGE_LIBGLIB2
@@ -18,8 +19,9 @@ config BR2_PACKAGE_LIBOSTREE
 
 	  https://ostree.readthedocs.io/en/latest/
 
-comment "libostree needs a uClibc or glibc toolchain w/ threads, dynamic library, wchar"
+comment "libostree needs a uClibc or glibc toolchain w/ threads, dynamic library, wchar, headers >= 5.4"
 	depends on !BR2_TOOLCHAIN_HAS_THREADS || BR2_STATIC_LIBS \
-		|| !BR2_USE_WCHAR || BR2_TOOLCHAIN_USES_MUSL
+		|| !BR2_USE_WCHAR || BR2_TOOLCHAIN_USES_MUSL || \
+		!BR2_TOOLCHAIN_HEADERS_AT_LEAST_5_4
 	depends on BR2_PACKAGE_LIBGPG_ERROR_ARCH_SUPPORTS
 	depends on BR2_USE_MMU