[install] torch.complex32 has been removed from 1.11.0

According to pytorch/pytorch#72721 complex32
will be brought back in a later version, the check should be removed
then.

asteroid/dsp/beamforming.py

@@ -473,14 +473,6 @@ def _generalized_eigenvalue_decomposition(a, b):
     return e_val, e_vec
 
 
-_to_double_map = {
-    torch.float16: torch.float64,
-    torch.float32: torch.float64,
-    torch.complex32: torch.complex128,
-    torch.complex64: torch.complex128,
-}
-
-
 def _common_dtype(*args):
     all_dtypes = [a.dtype for a in args]
     if len(set(all_dtypes)) > 1:
@@ -502,20 +494,24 @@ def force_double_linalg():
 
 
 def _precision_mapping():
+    has_complex32 = hasattr(torch, "complex32")
     if USE_DOUBLE:
-        return {
+        precision_map = {
             torch.float16: torch.float64,
             torch.float32: torch.float64,
-            torch.complex32: torch.complex128,
             torch.complex64: torch.complex128,
         }
+        if has_complex32:
+            precision_map[torch.complex32] = torch.complex128
     else:
-        return {
+        precision_map = {
             torch.float16: torch.float16,
             torch.float32: torch.float32,
-            torch.complex32: torch.complex32,
             torch.complex64: torch.complex64,
         }
+        if has_complex32:
+            precision_map[torch.complex32] = torch.complex32
+    return precision_map
 
 
 # Legacy