Add unit tests for traceback formatting of RecursionError

[Delgan]

For example, the following snippet:

from loguru import logger

def rec():
    rec()

try:
    rec()
except Exception:
    logger.exception("Oups")

Should produce the following logs:

2024-02-17 12:06:00.577 | ERROR    | __main__:<module>:9 - Oups
Traceback (most recent call last):

> File "/home/delgan/Code/loguru/script.py", line 7, in <module>
    rec()
    └ <function rec at 0x7a13f1314720>

  File "/home/delgan/Code/loguru/script.py", line 4, in rec
    rec()
    └ <function rec at 0x7a13f1314720>

  File "/home/delgan/Code/loguru/script.py", line 4, in rec
    rec()
    └ <function rec at 0x7a13f1314720>

  File "/home/delgan/Code/loguru/script.py", line 4, in rec
    rec()
    └ <function rec at 0x7a13f1314720>
  [Previous line repeated 996 more times]

RecursionError: maximum recursion depth exceeded

Note the "[Previous line repeated 996 more times]".