Citadel is shopping for U.S. oil production assets, including a previous bid for WildFire Energy before Magnolia Oil & Gas agreed to buy the Eagle Ford producer for $4.06 billion. Reuters reported Friday that the hedge fund and commodities trader has held talks with several private-equity owners of oil-weighted exploration and production companies in recent weeks. WildFire would have given Citadel roughly 53,000 barrels of oil equivalent per day of production, about 70% of it oil, plus 810,000 net acres in South Texas. Magnolia ultimately won…