[BUG] macOS arm64: Crash (SIGSEGV) on launch

[thecoder-001]

Describe the bug

Segfault on m2 mac running Ventura if processes with UIDs having no associated user are running.

To Reproduce

1. Install btop from homebrew
2. Compile and launch the following as root:

   
   #include <stdio.h>
   #include <stdlib.h>
   #include <unistd.h>

int main() { setuid(404); // or any other random unassigned uid printf("Current user ID: %d\n", getuid()); while (1) { sleep(10); } return 0; }

3. Try to launch btop
4. Ensure PROC box is enabled. If not, toggle with `4`
5. Segmentation fault.

**Expected behavior**

Should not segfault when proc box is displayed.

**Screenshots**
<img width="745" alt="Screenshot 2024-04-28 at 1 21 46 AM" src="https://github.com/aristocratos/btop/assets/25097841/6fe73cdc-8589-4441-ab1c-26ba64d49d6e">

**Info:**
 - btop++ version: 1.3.2
 - Binary: homebrew
 - Architecture: arm64
 - Platform: OsX
 - OSX release version: 14.4.1 (23E224)
 - Terminal used: iTerm2 (3.4.23)
 - Font used: MesloLGS NF

**Additional context**

Contents of `~/.config/btop/btop.log`

cat ~/.config/btop/btop.log 2024/04/28 (01:21:36) | ===> btop++ v.1.3.2 2024/04/28 (01:21:36) | WARNING: Failed to set locale UTF-8 continuing anyway.

2024/04/28 (01:27:10) | ===> btop++ v.1.3.2 2024/04/28 (01:27:10) | WARNING: Failed to set locale UTF-8 continuing anyway.

2024/04/28 (01:27:25) | ===> btop++ v.1.3.2 2024/04/28 (01:27:25) | DEBUG: Running in DEBUG mode! 2024/04/28 (01:27:25) | INFO: Logger set to DEBUG 2024/04/28 (01:27:25) | WARNING: Failed to set locale UTF-8 continuing anyway. 2024/04/28 (01:27:25) | INFO: Running on /dev/ttys008 2024/04/28 (01:27:25) | DEBUG: get_sensors(): show_coretemp=1 check_temp=1 2024/04/28 (01:27:25) | DEBUG: checking intel 2024/04/28 (01:27:25) | DEBUG: no intel sensors found

**GDB Backtrace**

<img width="889" alt="Screenshot 2024-04-28 at 1 32 32 AM" src="https://github.com/aristocratos/btop/assets/25097841/1f16736f-165d-409b-aac4-e6411fdf1492">

<img width="709" alt="Screenshot 2024-04-28 at 1 33 04 AM" src="https://github.com/aristocratos/btop/assets/25097841/08eae45e-9a8d-4b1a-acc9-94705fb087c6">

**Example responsible process:**
(after changes in btop_collect.cpp to log problematic processes)
`WARNING: Could not retrieve user information for user ID:502 (pid:43105)`

❯ ps -p 43105 -o uid,pid,user,args UID PID USER ARGS 502 43105 502 /usr/sbin/distnoted agent

<img width="671" alt="Screenshot 2024-04-28 at 3 19 10 AM" src="https://github.com/aristocratos/btop/assets/25097841/0bb2a581-dc9d-4e81-8713-4f644cd919ce">