Remove iostream include for C backend

pytensor/link/c/cmodule.py

@@ -157,7 +157,7 @@ class DynamicModule:
 
         self.support_code = []
         self.functions = []
-        self.includes = ["<Python.h>", "<iostream>", '"pytensor_mod_helper.h"']
+        self.includes = ["<Python.h>", '"pytensor_mod_helper.h"']
         self.init_blocks = []
 
     def print_methoddef(self, stream):

pytensor/tensor/blas.py

@@ -472,9 +472,7 @@ class GemmRelated(COp):
         return blas_header_text() + mod_str
 
     def c_headers(self, **kwargs):
-        # std.cout doesn't require the '%' symbol to print stuff...
-        # so it works much better with python's string-substitution stuff.
-        return ["<iostream>"]
+        return []
 
     def c_libraries(self, **kwargs):
         return ldflags()

pytensor/tensor/special.py

@@ -294,7 +294,7 @@ class Softmax(COp):
         return shape
 
     def c_headers(self, **kwargs):
-        return ["<iostream>", "<cmath>"]
+        return ["<cmath>"]
 
     def c_support_code_apply(self, node: Apply, name: str) -> str:
         """Needed to define NPY_RAVEL_AXIS"""