sys-fs/squashfs-tools: Sync with Gentoo

It's from Gentoo commit fd9f1d98700c206ddd5b374319f57a18aecc9d35.

sdk_container/src/third_party/portage-stable/sys-fs/squashfs-tools/files/squashfs-tools-4.7-missing-includes.patch

@@ -0,0 +1,37 @@
+From https://github.com/plougher/squashfs-tools/pull/314 (merged)
+From 05a895b3f996d1ac157d95b04980f5f047e7dbf7 Mon Sep 17 00:00:00 2001
+From: Ross Burton <ross.burton@arm.com>
+Date: Fri, 6 Jun 2025 15:23:07 +0100
+Subject: [PATCH] print_pager: add missing includes
+
+When building with musl:
+
+  print_pager.h:33:25: error: unknown type name 'pid_t'
+     33 | extern void wait_to_die(pid_t process);
+        |                         ^~~~~
+  print_pager.h:34:25: error: unknown type name 'pid_t'
+     34 | extern FILE *exec_pager(pid_t *process);
+        |                         ^~~~~
+
+print_pager.h uses pid_t and FILE, so add the required #includes to
+ensure that these are defined.
+
+Signed-off-by: Ross Burton <ross.burton@arm.com>
+---
+ squashfs-tools/print_pager.h | 3 +++
+ 1 file changed, 3 insertions(+)
+
+diff --git a/squashfs-tools/print_pager.h b/squashfs-tools/print_pager.h
+index c33d4d2e..f3e0da6c 100644
+--- a/squashfs-tools/print_pager.h
++++ b/squashfs-tools/print_pager.h
+@@ -30,6 +30,9 @@
+ #define MORE_PAGER 2
+ #define UNKNOWN_PAGER 3
+ 
++#include <stdio.h>
++#include <sys/types.h>
++
+ extern void wait_to_die(pid_t process);
+ extern FILE *exec_pager(pid_t *process);
+ extern int get_column_width();

sdk_container/src/third_party/portage-stable/sys-fs/squashfs-tools/squashfs-tools-4.7.ebuild

@@ -14,7 +14,7 @@ SRC_URI="
 
 LICENSE="GPL-2"
 SLOT="0"
-KEYWORDS="~alpha ~amd64 ~arm ~arm64 ~hppa ~loong ~m68k ~mips ~ppc ~ppc64 ~riscv ~s390 ~sparc ~x86"
+KEYWORDS="~alpha amd64 arm arm64 ~hppa ~loong ~m68k ~mips ppc ppc64 ~riscv ~s390 ~sparc x86"
 IUSE="debug lz4 lzma lzo xattr zstd"
 
 DEPEND="
@@ -27,6 +27,11 @@ DEPEND="
 "
 RDEPEND=${DEPEND}
 
+# https://bugs.gentoo.org/958646
+PATCHES=(
+	"${FILESDIR}/${P}-missing-includes.patch"
+)
+
 use10() {
 	usex "${1}" 1 0
 }