fix: use fmp provider for price_target endpoint

yfinance is not supported by obb.equity.estimates.price_target,
which only accepts benzinga or fmp.

openbb_service.py

@@ -106,7 +106,7 @@ async def get_financials(symbol: str) -> dict:
 async def get_price_target(symbol: str) -> float | None:
     try:
         result = await asyncio.to_thread(
-            obb.equity.estimates.price_target, symbol, provider=PROVIDER
+            obb.equity.estimates.price_target, symbol, provider="fmp"
         )
         items = _to_dicts(result)
         if items: