[Bug]: steamcmd.sh errors out when using updateonstart="on" (rustserver)

### User story

When using start with updateonstart="on", I want the server updated and then started. It just errors out while trying update and doesn't start.

### Game

Rust

### Linux distro

Ubuntu 24.04

### Command

command: start

### Further information

Tried to start my testing server with updateonstart="on". However steamcmd errors out without updating or starting the server. Using the update command normally or force-update command works fine and updates the server.

Any idea how I can fix this? Even after updating the server with the update command, the server won't start while updateonstart="on". I can only fix it by removing updateonstart="on" or setting it to off again. Which I don't want.

### Relevant log output

```shell
~$ ./rustserver st
[ INFO ] Starting rustserver: Running Carbon environment.sh
[ OK ] Updating rustserver: Checking for update: SteamCMD

Update available
* Local build: 17040988
* Remote build:
* Branch: public
https://steamdb.info/app/258550/

[ START ] Updating rustserver: SteamCMD
Branch: public
/home/rustserver/.local/share/Steam/steamcmd
/home/rustserver
steamcmd.sh[77171]: Couldn't find Steam root directory from /home/rustserver/.local/share/Steam/steamcmd/steamcmd.sh, aborting!
Complete! Updating rustserver: SteamCMD
~$
```

### Steps to reproduce

1. set updateonstart="on" in rustserver.cfg
2. use start command
3. error as above
4. update using either update or force-update
5. start again, still the same error