configs/roseapplepi: remove defconfig, broken

The roseapplepi defconfig fails to build u-boot since the move to GCC 15.x:

https://gitlab.com/buildroot.org/buildroot/-/jobs/11501385206

The issues are mainly related to missing includes, but given that the build
has been broken for a while, there is no mainline u-boot support for the
platform and the minimal kernel support has not seen any updates since it
was added for v5.15, just drop the defconfig.

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
(cherry picked from commit 56091a5818)
Signed-off-by: Thomas Perale <thomas.perale@mind.be>

DEVELOPERS

@@ -2583,7 +2583,6 @@ F:	board/librecomputer/lafrite/
 F:	board/nexbox/a95x/
 F:	board/openblocks/a6/
 F:	board/orangepi/
-F:	board/roseapplepi/
 F:	board/visionfive/
 F:	boot/shim/
 F:	configs/avenger96_defconfig
@@ -2595,7 +2594,6 @@ F:	configs/nezha_defconfig
 F:	configs/openblocks_a6_defconfig
 F:	configs/orangepi_pc_defconfig
 F:	configs/orangepi_r1_defconfig
-F:	configs/roseapplepi_defconfig
 F:	configs/sheevaplug_defconfig
 F:	configs/visionfive_defconfig
 F:	package/bats-core/