Avoid to invoke logging.info before calling logging.basicConfig.

When we call logging.info before calling logging.basicConfig,
logging.basicConfig may fail, so in the previous code, if our electron number is
missing, we would see an empty logging. So this commit does not logging the
information about missing electron number instead to save the logging basic
config.

Author: hzhangxyz

qmb/hubbard.py

@@ -29,7 +29,7 @@ class ModelConfig:
     # The coefficient of U
     u: typing.Annotated[float, tyro.conf.arg(aliases=["-u"])] = 0
 
-    # The electron number
+    # The electron number, left empty for half-filling
     electron_number: typing.Annotated[int | None, tyro.conf.arg(aliases=["-e"])] = None
 
     # The ref energy of the model
@@ -38,7 +38,6 @@ class ModelConfig:
     def __post_init__(self) -> None:
         if self.electron_number is None:
             self.electron_number = self.m * self.n
-            logging.info("Electron number is not specified, set to half-filling (one electron per lattice site) %d", self.electron_number)
 
         if self.m <= 0 or self.n <= 0:
             raise ValueError("The dimensions of the Hubbard model must be positive integers.")