fix: Correctly search num_experts_per_tok as optional

Co-authored-by: Sigbjørn Skjæret <[email protected]>

Author: gabe-l-hart

convert_hf_to_gguf.py

@@ -7662,7 +7662,7 @@ def __init__(self, *args, **kwargs):
         # "granite" or "granitemoe" model
         if not self._ssm_layers:
             old_arch = self.gguf_writer.arch
-            has_experts = self.find_hparam(["num_experts_per_tok"])
+            has_experts = self.find_hparam(["num_experts_per_tok"], optional=True)
             new_arch = (
                 gguf.MODEL_ARCH_NAMES[gguf.MODEL_ARCH.GRANITE_MOE]
                 if has_experts else