BUG: Remove x_validate and y_validate as they're unnecessary (#266)

Author: blkboxeconomist

lectures/jax_nn.md

@@ -444,8 +444,6 @@ def train_jax_model(
         θ: list,                    # Initial parameters (pytree)
         x: jnp.ndarray,             # Training input data
         y: jnp.ndarray,             # Training target data
-        x_validate: jnp.ndarray,    # Validation input data
-        y_validate: jnp.ndarray,    # Validation target data
         config: Config              # contains configuration data
     ):
     """
@@ -473,12 +471,12 @@ param_key = jax.random.PRNGKey(1234)
 θ = initialize_network(param_key, config)
 
 # Warmup run to trigger JIT compilation
-train_jax_model(θ, x_train, y_train, x_validate, y_validate, config)
+train_jax_model(θ, x_train, y_train, config)
 
 # Reset and time the actual run
 θ = initialize_network(param_key, config)
 start_time = time()
-θ = train_jax_model(θ, x_train, y_train, x_validate, y_validate, config)
+θ = train_jax_model(θ, x_train, y_train, config)
 θ[0].W.block_until_ready()  # Ensure computation completes
 jax_runtime = time() - start_time