[CLN] Use consistent numeric formatting for readability

Replaced `100000000` with `100_000_000` to improve code readability and maintain uniform number formatting. This change does not alter functionality.

Author: Leguark

gempy_engine/API/interp_single/_interp_scalar_field.py

@@ -117,7 +117,7 @@ def _optimize_nuggets_against_condition_number(A_matrix, interp_input, kernel_op
     cond_number = BackendTensor.t.linalg.cond(A_matrix)
     nuggets = interp_input.sp_internal.nugget_effect_ref_rest
     l1_reg = torch.norm(nuggets, 2) ** 2
-    lambda_l1 = 100000000
+    lambda_l1 = 100_000_000
     loss = cond_number - lambda_l1 * l1_reg
     loss.backward()
     kernel_options.condition_number = cond_number