LONDON—Brent crude futures snapped a three-day rally on Friday in light trading before the Christmas holidays but the benchmark was still headed for a weekly gain, with the market focusing on next steps by OPEC+ and the impact of the Omicron variant. Brent crude futures fell 75 cents, or 1 percent, to $76.10 a barrel by 1121 GMT, following a 2.1 percent gain in the previous session. The benchmark was still on track for a weekly gain of about 3.5 percent. U.S. markets are closed on Friday for the Christmas holiday. Oil prices have recovered this week as fears over the impact of the highly infectious Omicron variant on the global economy receded, with early data suggesting it causes a milder level of illness. “The omicron-is-mild rally could well continue into January now, but reality will bite in February I believe, as the end of the Fed taper moves into …