get more conservative with twelvedata

src/providers/twelvedata.zig

@@ -28,7 +28,9 @@ pub const TwelveData = struct {
         return .{
             .api_key = api_key,
             .client = http.Client.init(allocator),
-            .rate_limiter = RateLimiter.perMinute(8),
+            // Provider is 8/min, but we seem to be bumping against it, so we
+            // will be a bit more conservative here. Slow and steady
+            .rate_limiter = RateLimiter.perMinute(7),
             .allocator = allocator,
         };
     }