Update to v6.3 kernel headers.

Kernel headers coming from:

Git: https://android.googlesource.com/kernel/common/
Branch: android-mainline
Tag: android-mainline-6.3

Test: Bionic unit tests pass.
Change-Id: I5270ef291a77343e47ef3a5fbd02b8cacf218ec5
diff --git a/libc/kernel/uapi/linux/fcntl.h b/libc/kernel/uapi/linux/fcntl.h
index a46726b..05393d5 100644
--- a/libc/kernel/uapi/linux/fcntl.h
+++ b/libc/kernel/uapi/linux/fcntl.h
@@ -34,6 +34,7 @@
 #define F_SEAL_GROW 0x0004
 #define F_SEAL_WRITE 0x0008
 #define F_SEAL_FUTURE_WRITE 0x0010
+#define F_SEAL_EXEC 0x0020
 #define F_GET_RW_HINT (F_LINUX_SPECIFIC_BASE + 11)
 #define F_SET_RW_HINT (F_LINUX_SPECIFIC_BASE + 12)
 #define F_GET_FILE_RW_HINT (F_LINUX_SPECIFIC_BASE + 13)