updating header to not include multiboot with alloc

multiboot2-header/Cargo.toml

@@ -47,7 +47,7 @@ derive_more.workspace = true
 # log.workspace = true
 
 # used for MBI tags
-multiboot2 = "0.19.0"
+multiboot2 = { version = "0.19.0", default-features = false }
 
 [package.metadata.docs.rs]
 all-features = true