Fix Cython 3 compilation: remove Python 2 long type from encode_func

In Python 3, `long` doesn't exist (unified with `int`). Cython 3
rejects `long` as a Python type identifier. Remove the `long: encode_long`
entry and route `int` to the untyped `encode_long` handler so
arbitrary-size Python integers are supported.

Co-authored-by: whtsky <876694+whtsky@users.noreply.github.com>

Author: Copilot

bencoder.pyx

@@ -147,9 +147,8 @@ cdef encode_dict(x, list r):
 
 
 encode_func = {
-    int: encode_int,
-    bool: encode_int,    
-    long: encode_long,
+    int: encode_long,
+    bool: encode_int,
     bytes: encode_bytes,
     str: encode_string,
     list: encode_list,