Enforce --write-changes in interactive mode

By modifying the initial value of interactive and directly modifying
the value of write_changes when the user selects the interactive model
But I don't think this is the best solution, because codespell doesn't
make any limitations on the value of interactive entered by the user,
while the execution only supports 0, 1, 2, 3.

Author: MercuryDemo

codespell_lib/_codespell.py

@@ -507,7 +507,7 @@ def parse_options(
         "--interactive",
         action="store",
         type=int,
-        default=0,
+        default=-1,
         help="set interactive mode when writing changes:\n"
         "- 0: no interactivity.\n"
         "- 1: ask for confirmation.\n"
@@ -1139,6 +1139,9 @@ def main(*args: str) -> int:
         for ifile, cfg_file in enumerate(used_cfg_files, start=1):
             print(f"    {ifile}: {cfg_file}")
 
+    if options.interactive >= 0:
+        options.write_changes = True
+
     if options.regex and options.write_changes:
         print(
             "ERROR: --write-changes cannot be used together with --regex",