Global search and replace with regex does not correctly replace #2803

Describe the problem

A sketch was delivered with additional line feeds; demo code below

#define hello

#include <SoftwareSerial.h>

#include <FastLED.h>

void setup() {

}

void loop() {
}

E.g. between the two include statements

A search correctly finds them

but a replace does not work correctly / as expected; replacing \n\n with \n results in the below

#define hello\n

#include <SoftwareSerial.h>\n

#include <FastLED.h>\n

void setup() {\n

}\n

void loop() {
}

To reproduce

Create a sketch with some additional empty lines.
Try to replace using a regular expression

Expected behavior

The expected behaviour is that additional empty lines are removed.

Arduino IDE version

2.3.7-nightly-20251025

Operating system

Windows

Operating system version

Win 11

Additional context

Detected while using IDE 2.3.6.
Sketch was not saved.

Issue checklist

• I searched for previous reports in the issue tracker
• I verified the problem still occurs when using the latest nightly build
• My report contains all necessary details