Strip function body of CodeInput (#92)

This removes the linebreak at the end which results in undesired
formatting in the `CodeInput`.

src/scwidgets/code/_widget_code_input.py

@@ -251,7 +251,7 @@ def get_function_body(function: types.FunctionType) -> str:
                 line[leading_indent:] if line.strip() else "" for line in lines
             )
 
-        return source
+        return source.strip()
 
     @property
     def function(self) -> types.FunctionType:

tests/test_code.py

@@ -85,19 +85,19 @@ def test_get_docstring(self):
     def test_get_function_body(self):
         assert (
             CodeInput.get_function_body(self.mock_function_1)
-            == "if x > 0:\n    return x + y\nelse:\n    return y + z()\n"
+            == "if x > 0:\n    return x + y\nelse:\n    return y + z()"
         )
-        assert CodeInput.get_function_body(self.mock_function_2) == "return x\n"
-        assert CodeInput.get_function_body(self.mock_function_3) == "return x\n"
+        assert CodeInput.get_function_body(self.mock_function_2) == "return x"
+        assert CodeInput.get_function_body(self.mock_function_3) == "return x"
         assert (
             CodeInput.get_function_body(self.mock_function_4)
-            == "return x  # noqa: E702\n"
+            == "return x  # noqa: E702"
         )
         assert (
             CodeInput.get_function_body(self.mock_function_5)
-            == "def x():\n    return 5\nreturn x()\n"
+            == "def x():\n    return 5\nreturn x()"
         )
-        assert CodeInput.get_function_body(self.mock_function_6) == "return x\n"
+        assert CodeInput.get_function_body(self.mock_function_6) == "return x"
         with pytest.raises(
             ValueError,
             match=r"Did not find any def definition. .*",