Panic in grid.rs when opening new pane

[aidanhs]

2. Issues with the Zellij UI / behavior / crash

Issue description

Tried to open a new pane in a terminal window inside of vscode.

Possibly relevant info:

• I had a multi-tab multi-pane session, attached to from multiple terminal windows
• another terminal window attached with unusual dimensions (very short vertically, very wide horizontally)
• from this narrow window I closed a few panes, then tried to open another with alt+n

Error occurred in server:

  × Thread 'screen' panicked.
  ├─▶ Originating Thread(s)
  │     1. stdin_handler_thread: AcceptInput
  │     2. pty_thread: SpawnTerminal
  │     3. screen_thread: NewPane
  │   
  ├─▶ At zellij-server/src/panes/grid.rs:1381:30
  ╰─▶ called `Option::unwrap()` on a `None` value
  help: If you are seeing this message, it means that something went wrong.
        
        -> To get additional information, check the log at: /tmp/zellij-1000/zellij-log/zellij.log
        -> To see a backtrace next time, reproduce the error with: RUST_BACKTRACE=1 zellij [...]
        -> To help us fix this, please open an issue: https://github.com/zellij-org/zellij/issues

There doesn't seem to be anything of relevance in the log

Minimal reproduction

Not sure how to reproduce, but wanted to get the error reported. Happy to close given the minimal detail, now there's a record of it happening for others.

Other relevant information

Using zellij 0.40.1