package/bitcoin: Fix build without SSP

Buildroot commit fabcd7c8cc bumped the
package from 28.0 to 30.0 which includes upstream commit
a01cb6e63f
that was first included in version 29.0 and added among others
-fstack-protector-all to cxx_flags guarded with a new configure option
ENABLE_HARDENING which default to ON.

This commit causes build errors with toolchains with SSP support:

[ 44%] Linking CXX executable ../bin/bitcoin
/home/autobuild/autobuild/instance-40/output-1/host/lib/gcc/i686-buildroot-linux-musl/15.2.0/../../../../i686-buildroot-linux-musl/bin/ld:
 CMakeFiles/bitcoin.dir/bitcoin.cpp.o:
 in function `fs::PathToString(fs::path const&)':
bitcoin.cpp:(.text+0x4c):
 undefined reference to `__stack_chk_fail_local'

Upstream later removed the forementioned configure option with commit
00ba3ba303
that was first included in version 30.0 so we need to remove
-fstack-protector-all from CMakeLists.txt.

Fixes:
https://autobuild.buildroot.net/results/093/093253c79fed1c5b93decc3124e9ef4622168efe/

Signed-off-by: Bernd Kuhls <bernd@kuhls.net>
Signed-off-by: Julien Olivain <ju.o@free.fr>
(cherry picked from commit ed51b4b691)
Signed-off-by: Thomas Perale <thomas.perale@mind.be>

package/bitcoin/0002-CMakeLists.txt-Don-t-force-fstack-protector.patch

@@ -0,0 +1,30 @@
+From 4d33b5bcc924c9271c40a19796f8316ba6aaa276 Mon Sep 17 00:00:00 2001
+From: Bernd Kuhls <bernd@kuhls.net>
+Date: Sat, 18 Jul 2026 08:10:21 +0200
+Subject: [PATCH] CMakeLists.txt: Don't force -fstack-protector
+
+This allows the environment to decide whether SSP should be used or
+not, for example to support toolchains that don't have SSP support.
+
+Upstream: N/A Buildroot specific
+
+Signed-off-by: Bernd Kuhls <bernd@kuhls.net>
+---
+ CMakeLists.txt | 1 -
+ 1 file changed, 1 deletion(-)
+
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 892f30d94b..93ccbf71ec 100644
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -532,7 +532,6 @@ else()
+   unset(cxx_supports_fortify_source)
+ 
+   try_append_cxx_flags("-Wstack-protector" TARGET core_interface SKIP_LINK)
+-  try_append_cxx_flags("-fstack-protector-all" TARGET core_interface)
+   try_append_cxx_flags("-fcf-protection=full" TARGET core_interface)
+ 
+   if(MINGW)
+-- 
+2.47.3
+