LONDON—Oil prices were on track for their biggest weekly gain since late August, with market sentiment buoyed by easing concerns over the Omicron coronavirus variant’s impact on global economic growth and fuel demand. The Brent and WTI benchmarks were both on course for gains of more than 7 percent this week, their first weekly gain in seven, even after a brief bout of profit-taking. Brent crude futures were up 66 cents, or 0.9 percent, at $75.08 a barrel by 1141 GMT after falling 1.9 percent on Thursday. U.S. West Texas Intermediate (WTI) crude futures rose 74 cents, or 1 percent, to $71.68 after sliding 2 percent in a volatile session the previous day. Earlier in the week, the oil market had recovered about half the losses suffered since the Omicron outbreak on Nov. 25, with prices lifted by early studies suggesting that three doses of Pfizer’s COVID-19 vaccine offers protection …