ci: Move partition table offset in secure boot test app

tools/test_apps/security/secure_boot/sdkconfig.defaults

@@ -0,0 +1,6 @@
+# Default Secure Boot bootloader is too large to fit in default
+# bootloader size without adding 0x1000 bytes or reducing the log level.
+#
+# If you find yourself needing to edit this in the future, it's a sign the
+# bootloader is bloating out!
+CONFIG_PARTITION_TABLE_OFFSET=0xA000