fix python 3.11 err with f-strings

Author: jakelorocco

test/backends/test_tool_helpers.py

@@ -53,7 +53,7 @@ def get_weather(location: str) -> int:
     assert tools["get_weather"] == get_weather
 
     # Must use `==` for bound methods.
-    assert tools["tool1"] == ftc.tool1, f"{tools["tool1"]} should == {ftc.tool1}"
+    assert tools["tool1"] == ftc.tool1, f"{tools['tool1']} should == {ftc.tool1}"
 
 
 def test_add_tools_from_model_options_map():