osc.lua: ignore seek ranges without usable duration

seekRangesF() accepts a zero duration and produces NaN/Inf coordinates,
which assdraw cannot format. Ignore seek-range metadata when the native
duration property is unavailable or zero.

Fixes #18344

player/lua/osc.lua

@@ -2533,7 +2533,7 @@ local function osc_init()
         if user_opts.seekrangestyle == "none" or not cache_enabled() then
             return nil
         end
-        if state.duration == nil then
+        if state.duration == nil or state.duration == 0 then
             return nil
         end
         local nranges = {}