Adapt to js_env.start change

Signed-off-by: Francis Bouvier <francis@lightpanda.io>

src/main_shell.zig

@@ -16,7 +16,7 @@ fn execJS(
 ) !void {
 
     // start JS env
-    js_env.start(apis);
+    try js_env.start(alloc, apis);
     defer js_env.stop();
 
     // alias global as self and window