Merge pull request #531 from qiboteam/cuquantumprint

Fix `test_prints.py` when cuquantum is installed

src/qibo/tests/test_prints.py

@@ -17,7 +17,7 @@ def __init__(self, code, filedir=None):
     @classmethod
     def from_file(cls, filedir):
         assert filedir[-3:] == ".py"
-        with open(filedir, "r") as file:
+        with open(filedir, "r", encoding="utf-8") as file:
             code = file.read()
         return cls(code, filedir)