$BASH hardcoded to `/bin/bash` when it should be `/opt/homebrew/bin/bash`

Describe the bug

set shell to Bash (Custom) - /opt/homebrew/bin/bash

start Warp

run these cmds...

$ echo $BASH
/bin/bash

$ echo $BASH_VERSION
5.2.15(1)-release

$ /bin/bash --version
GNU bash, version 3.2.57(1)-release (arm64-apple-darwin22)
Copyright (C) 2007 Free Software Foundation, Inc.

something is off... ? Does not happen in iTerm2 or Terminal.

Expected behavior

$ echo $BASH
/opt/homebrew/bin/bash

Screenshots

Operating system

MacOS

Operating system and version

13.5.1

Shell Version

5.2.15(1)

Current Warp version

v0.2023.08.29.08.04.stable_00

Regression

No, this bug or issue has existed throughout my experience using Warp

Is this a Warp specific issue? (i.e. does it happen in Terminal, iTerm, Kitty, etc.)

Yes, this I confirmed this only happens in Warp, not other terminals.

Warp Internal (ignore): linear-label:b8107fdf-ba31-488d-b103-d271c89cac3e

None

Start by reproducing the issue in Warp on macOS 13.5.1 with the custom shell set to /opt/homebrew/bin/bash, then inspect the shell-launch and environment initialization paths. No source file or test is named; done means $BASH reports /opt/homebrew/bin/bash without breaking the reported Bash version behavior.