fix(wasm_sandbox): drop trailing None from map_file_cow call

hyperlight-host 0.16.0 dropped the third `Option` argument on
`MultiUseSandbox::map_file_cow`. Without this fix the bump to
host 0.16 fails to compile with E0061 unexpected argument.

Signed-off-by: Yordis Prieto <yordis.prieto@gmail.com>

Author: yordis

src/hyperlight_wasm/src/sandbox/wasm_sandbox.rs

@@ -226,7 +226,7 @@ impl WasmSandbox {
         self.clean_inner()?;
 
         self.inner.load_via_fn(|inner| {
-            if let Ok(len) = inner.map_file_cow(file.as_ref(), MAPPED_BINARY_VA, None) {
+            if let Ok(len) = inner.map_file_cow(file.as_ref(), MAPPED_BINARY_VA) {
                 inner.call::<()>("LoadWasmModulePhys", (MAPPED_BINARY_VA, len))?;
             } else {
                 let wasm_bytes = std::fs::read(file)?;