[Bugfix][ROCm] Create linear layer biases with requires_grad=False (#56161)

Signed-off-by: Micah Williamson <micah.williamson@amd.com>

.buildkite/test-amd.yaml

@@ -4022,7 +4022,7 @@ steps:
 #------------------------------------------------------  mi355 · weight_loading  -------------------------------------------------------#
 
 - label: ":amd: (MI355) Weight Loading Multi-GPU" # TBD
-  timeout_in_minutes: 30
+  timeout_in_minutes: 40
   mirror_hardwares: [amdexperimental, amdproduction, amdgfx950nightly, amdmi355]
   dind: false
   agent_pool: mi355_2

vllm/model_executor/layers/linear.py

@@ -380,7 +380,8 @@ class ReplicatedLinear(LinearBase):
 
         if bias:
             self.bias = Parameter(
-                torch.empty(self.output_size, dtype=self.params_dtype)
+                torch.empty(self.output_size, dtype=self.params_dtype),
+                requires_grad=False,
             )
             set_weight_attrs(
                 self.bias,
@@ -525,7 +526,8 @@ class ColumnParallelLinear(LinearBase):
 
         if bias:
             self.bias = Parameter(
-                torch.empty(self.output_size_per_partition, dtype=params_dtype)
+                torch.empty(self.output_size_per_partition, dtype=params_dtype),
+                requires_grad=False,
             )
             set_weight_attrs(
                 self.bias,
@@ -1708,7 +1710,10 @@ class RowParallelLinear(LinearBase):
             )
 
         if bias:
-            self.bias = Parameter(torch.empty(self.output_size, dtype=params_dtype))
+            self.bias = Parameter(
+                torch.empty(self.output_size, dtype=params_dtype),
+                requires_grad=False,
+            )
             set_weight_attrs(
                 self.bias,
                 {