patch error with linux-cachyos-lts 6.12.14

[mabod]

On Endeavouros the build fails for kernel 6.12.14. Patching stops with error:

╰─# makepkg
...
patching file arch/x86/boot/compressed/Makefile
Reversed (or previously applied) patch detected!  Skipping patch.
1 out of 1 hunk ignored -- saving rejects to file arch/x86/boot/compressed/Makefile.rej
patching file arch/x86/include/asm/futex.h
patching file arch/x86/mm/tlb.c
patching file drivers/firmware/efi/libstub/Makefile
Reversed (or previously applied) patch detected!  Skipping patch.
1 out of 1 hunk ignored -- saving rejects to file drivers/firmware/efi/libstub/Makefile.rej
...
patching file lib/zstd/zstd_common_module.c
patching file lib/zstd/zstd_compress_module.c
patching file lib/zstd/zstd_decompress_module.c
==> ERROR: A failure occurred in prepare().
    Aborting...

content of
src/linux-6.12.14/arch/x86/boot/compressed/Makefile.rej :

╰─# cat src/linux-6.12.14/arch/x86/boot/compressed/Makefile.rej
--- arch/x86/boot/compressed/Makefile
+++ arch/x86/boot/compressed/Makefile
@@ -25,6 +25,7 @@ targets := vmlinux vmlinux.bin vmlinux.bin.gz vmlinux.bin.bz2 vmlinux.bin.lzma \
 # avoid errors with '-march=i386', and future flags may depend on the target to
 # be valid.
 KBUILD_CFLAGS := -m$(BITS) -O2 $(CLANG_FLAGS)
+KBUILD_CFLAGS += -std=gnu11
 KBUILD_CFLAGS += -fno-strict-aliasing -fPIE
 KBUILD_CFLAGS += -Wundef
 KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING

content of
src/linux-6.12.14/drivers/firmware/efi/libstub/Makefile.rej :

╰─# cat src/linux-6.12.14/drivers/firmware/efi/libstub/Makefile.rej
--- drivers/firmware/efi/libstub/Makefile
+++ drivers/firmware/efi/libstub/Makefile
@@ -11,7 +11,7 @@ cflags-y			:= $(KBUILD_CFLAGS)
 
 cflags-$(CONFIG_X86_32)		:= -march=i386
 cflags-$(CONFIG_X86_64)		:= -mcmodel=small
-cflags-$(CONFIG_X86)		+= -m$(BITS) -D__KERNEL__ \
+cflags-$(CONFIG_X86)		+= -m$(BITS) -D__KERNEL__ -std=gnu11 \
 				   -fPIC -fno-strict-aliasing -mno-red-zone \
 				   -mno-mmx -mno-sse -fshort-wchar \
 				   -Wno-pointer-sign \