Britney Spears, at the ripe old age of 22, has released four albums in the last five and a half years. By MTV standards, that makes her a grizzled veteran, so maybe it's apt that her next release will be a greatest hits album. MTV News reports that, on Nov. 16, Spears will release a collection called ''Greatest Hits: My Prerogative.'' As the title suggests, one of two new songs on the CD will be a cover of a golden oldie first recorded when Spears was 6: Bobby Brown's ''My Prerogative.'' Brown's signature hit was a prescient rant aimed at a press that he felt wouldn't let him make his own mistakes, a sentiment that the ''I'm Not a Girl, Not Yet a Woman'' singer can surely identify with. The single will hit radio on Sept. 14. Maybe Brown should return the favor and cover ''Oops, I Did It Again.''