[Misc] Update type annotation for rotary embedding base (#18914)

Signed-off-by: DarkLight1337 <tlleungac@connect.ust.hk>

vllm/model_executor/models/minimax_text_01.py

@@ -141,7 +141,7 @@ class MiniMaxText01RotaryEmbedding(CustomOp):
         head_size: int,
         rotary_dim: int,
         max_position: int,
-        base: int,
+        base: float,
         is_neox_style: bool,
         cache_dtype: torch.dtype,
     ) -> None:
@@ -155,10 +155,7 @@ class MiniMaxText01RotaryEmbedding(CustomOp):
         cache = self._compute_cos_sin_cache().to(cache_dtype)
         self.register_buffer("cos_sin_cache", cache, persistent=False)
 
-    def _compute_inv_freq(
-        self,
-        base: Union[int, float],
-    ) -> torch.Tensor:
+    def _compute_inv_freq(self, base: float) -> torch.Tensor:
         """Compute the inverse frequency."""
         inv_freq = 1.0 / (base**(torch.arange(
             0, self.rotary_dim, 2, dtype=torch.float) / self.rotary_dim))