package/linux-headers: drop 6.9.x option

The 6.9.x series is now EOL upstream, so drop the linux-headers option
and add legacy handling for it.

Signed-off-by: Bernd Kuhls <bernd@kuhls.net>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

Config.in.legacy

@@ -146,6 +146,13 @@ endif
 
 comment "Legacy options removed in 2024.08"
 
+config BR2_KERNEL_HEADERS_6_9
+	bool "kernel headers version 6.9.x are no longer supported"
+	select BR2_LEGACY
+	help
+	  Version 6.9.x of the Linux kernel headers are no longer
+	  maintained upstream and are now removed.
+
 config BR2_x86_knightslanding
 	bool "knightslanding x86 architecture support dropped"
 	select BR2_LEGACY

linux/linux.hash

@@ -1,6 +1,5 @@
 # From https://www.kernel.org/pub/linux/kernel/v6.x/sha256sums.asc
 sha256  fa5f22fd67dd05812d39dca579320c493048e26c4a556048a12385e7ae6fc698  linux-6.10.3.tar.xz
-sha256  5ae7cc4e0e2f6b9ba630f643985ba0522c7d5e5b9571ba478a3cb513edd4cf22  linux-6.9.12.tar.xz
 sha256  93218296934915636fe6ba08e125948424cc270fd8948502c0ab91087a9fccd8  linux-6.6.44.tar.xz
 sha256  5eb4706f898f50881552ff5146d892132d3ffc5298033bffe27087d3a44c4573  linux-6.1.103.tar.xz
 # From https://www.kernel.org/pub/linux/kernel/v5.x/sha256sums.asc

package/linux-headers/Config.in.host

@@ -48,10 +48,6 @@ config BR2_KERNEL_HEADERS_6_6
 	bool "Linux 6.6.x kernel headers"
 	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_6_6
 
-config BR2_KERNEL_HEADERS_6_9
-	bool "Linux 6.9.x kernel headers"
-	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_6_9
-
 config BR2_KERNEL_HEADERS_6_10
 	bool "Linux 6.10.x kernel headers"
 	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_6_10
@@ -433,7 +429,6 @@ config BR2_DEFAULT_KERNEL_HEADERS
 	default "5.15.164"	if BR2_KERNEL_HEADERS_5_15
 	default "6.1.103"	if BR2_KERNEL_HEADERS_6_1
 	default "6.6.44"	if BR2_KERNEL_HEADERS_6_6
-	default "6.9.12"	if BR2_KERNEL_HEADERS_6_9
 	default "6.10.3"	if BR2_KERNEL_HEADERS_6_10
 	default BR2_DEFAULT_KERNEL_VERSION if BR2_KERNEL_HEADERS_VERSION
 	default "custom"	if BR2_KERNEL_HEADERS_CUSTOM_TARBALL