Fix crypttab python3 compatibility issue (#30457)

In python2 str gives byte string. In Python3 it gives unicode string so it
can't be written in a binary mode opened file.
Use to_bytes helper function to ensure content being written will be
properly encoded in both python2 and python3.

lib/ansible/modules/system/crypttab.py

@@ -89,7 +89,7 @@ import os
 import traceback
 
 from ansible.module_utils.basic import AnsibleModule
-from ansible.module_utils._text import to_native
+from ansible.module_utils._text import to_bytes, to_native
 
 def main():
 
@@ -169,7 +169,7 @@ def main():
     if changed and not module.check_mode:
         try:
             f = open(path, 'wb')
-            f.write(str(crypttab))
+            f.write(to_bytes(crypttab, errors='surrogate_or_strict'))
         finally:
             f.close()