Use warn level for Provider fallback catch

The Provider catch is defense-in-depth for when FlagEvalMetrics
class itself can't load (OTel API absent entirely). The detailed
error message is logged inside FlagEvalMetrics when it CAN load
but SDK init fails. Using error level here caused the openfeature
smoke test to fail (it asserts no ERROR entries in application logs).

Author: typotter

products/feature-flagging/feature-flagging-api/src/main/java/datadog/trace/api/openfeature/Provider.java

@@ -52,7 +52,9 @@ public Provider(final Options options) {
         metrics = new FlagEvalMetrics();
         hook = new FlagEvalHook(metrics);
       } catch (LinkageError | Exception e) {
-        log.error("Failed to initialize evaluation metrics — metrics disabled", e);
+        // FlagEvalMetrics logs the detailed error when it can load but OTel SDK init fails.
+        // This outer catch fires when the class itself can't load (OTel API absent entirely).
+        log.warn("Evaluation metrics unavailable — OTel classes not on classpath", e);
       }
     }
     this.flagEvalMetrics = metrics;