The Lock field on containers and the minecraft:lock item stack data component do not get datafixed correctly when a backslash is present.

Steps to reproduce (container block):

1. Place a container block with a lock in a world in 1.21.1:

   /setblock ~ ~ ~ minecraft:chest{Lock:"\\"}

2. Observe how the lock string is

   "\\"

    when checked using the data command:

   /data get block ~ ~ ~ Lock

3. Load the world in 24w39a.
4. Observe how the lock is gone:

   /data get block ~ ~ ~ lock

   There is also no error present in the logs.

Steps to reproduce (minecraft:lock item stack data component):

1. Give yourself the following item stack in 1.21.1:

   /give @s stick[minecraft:lock="\\"]

2. Observe how the minecraft:lock data component is

   "\\"

    when holding the item stack and checked using the data command:

   /data get entity @s SelectedItem.components."minecraft:lock"

3. Load the world in 24w39a.
4. Observe how the minecraft:lock data component is empty:

   /data get entity @s SelectedItem.components."minecraft:lock"

   In the logs the following error is also present (see latest.log):

   Tried to load invalid item: 'com.google.gson.stream.MalformedJsonException: Unterminated string at line 1 column 4 path $ missed input: {"minecraft:custom_name":'"\\"'} missed input: {"minecraft:lock":{components:{"minecraft:custom_name":'"\\"'}}}'