By Eric Onstad LONDON (Reuters) – Britain’s tax authorities have filed winding up petitions for several steel businesses owned by the GFG Alliance controlled by commodities tycoon Sanjeev Gupta, court records showed. Gupta’s family conglomerate GFG has been scrambling to arrange financing to rescue his cash-starved web of businesses in steel, aluminium and energy after supply chain finance firm Greensill filed for insolvency in March last year. The tax authority, HM Revenue & Customs, filed winding up petitions on Monday for at least three GFG UK businesses, including Liberty Performance Steel…