chore: update to latest fastapi (#2240)

security alert https://github.com/lnbits/lnbits/security/dependabot/46

lnbits/jinja2_templating.py

@@ -8,8 +8,8 @@ from starlette.templating import Jinja2Templates as SuperJinja2Templates
 
 class Jinja2Templates(SuperJinja2Templates):
     def __init__(self, loader: BaseLoader) -> None:
-        super().__init__("")
         self.env = self.get_environment(loader)
+        super().__init__(env=self.env)
 
     def get_environment(self, loader: BaseLoader) -> Environment:
         @pass_context

lnbits/middleware.py

@@ -187,7 +187,12 @@ class ExtensionsRedirectMiddleware:
 
 def add_ratelimit_middleware(app: FastAPI):
     core_app_extra.register_new_ratelimiter()
-    app.add_exception_handler(RateLimitExceeded, _rate_limit_exceeded_handler)
+    # latest https://slowapi.readthedocs.io/en/latest/
+    # shows this as a valid way to add the handler
+    app.add_exception_handler(
+        RateLimitExceeded,
+        _rate_limit_exceeded_handler,  # type: ignore
+    )
     app.add_middleware(SlowAPIMiddleware)