cffi: accept floats in cast

For reference, see https://github.com/python-cffi/cffi/blob/2079ca7d16a7b847d823fc37887b55745e0cec9e/src/cffi/backend_ctypes.py#L417-L430

Author: aochagavia

stubs/cffi/cffi/api.pyi

@@ -43,7 +43,7 @@ class FFI:
         free: Callable[[CData], Any] | None = None,
         should_clear_after_alloc: bool = True,
     ) -> _cffi_backend._Allocator: ...
-    def cast(self, cdecl: str | CType, source: CData | int) -> CData: ...
+    def cast(self, cdecl: str | CType, source: CData | int | float) -> CData: ...
     def string(self, cdata: CData, maxlen: int = -1) -> bytes | str: ...
     def unpack(self, cdata: CData, length: int) -> bytes | str | list[Any]: ...
     @overload