UI Incorrectly Escaping Tab Symbol in Delimiter Field for Source S3

### Topic

UI Incorrectly Escaping Tab Symbol in Delimiter Field

### Revelant information

When inputting the tab character as a delimiter in the UI, it is being incorrectly escaped with an additional backslash, resulting in "\\\t" instead of the expected "\t". This causes an error when the system tries to process the delimiter.

**Error Message:**

```
streams -> 0 -> format -> delimiter
delimiter should only be one character (type=value_error)
```
**Steps to Reproduce:**

1. Navigate to the section where the delimiter can be set.
2. Input the tab character as the delimiter.
3. Observe that the system processes it as "\\\t" instead of "\t".
4. The above error message is displayed.

**Expected Behavior:**
The tab character should be recognized as "\t" without any additional escape characters.

**Actual Behavior:**
The system is adding an additional escape character, resulting in "\\\t".

**Screenshots:**
**Comment**: The modified delimiter is visible in the second screenshot.