This was more painful that I expected but will allow `brew bundle sh`
and `brew sh` to use the user's configuration but use our custom prompt
for Bash and ZSH.
It's both unexpected and undesirable for `brew bundle (exec|env|sh)` to
filter the environment and makes these tools less useful.
Not filtering the environment, though, causes issues with the
`brew bundle sh` shell. Fix this up and, while we're here, also improve
the formatting for both `zsh` and `bash` (the default) to use nicer and
more consistent prompts and colours.
To simplify this, consolidate some logic in a new
`Utils::Shell.shell_with_prompt` method and add tests for it and a
similar notice for `brew bundle sh`.
Finally, avoid printing out the notice when `HOMEBREW_NO_ENV_HINTS` is
set.
I know that we're outside our normal deprecation cycle but: these are
totally broken with the API and it doesn't make sense to support them
only for non-core formulae.
Since the `fish_add_path` command modifies a universal Fish variable
(which is automatically persisted to a file) it's unnecessary to run it
again every time a new shell is opened.
fixes https://github.com/Homebrew/brew/issues/8965
See Fish docs https://fishshell.com/docs/current/tutorial.html#path.
> A faster way is to use the `fish_add_path function`... The advantage is that
> you don't have to go mucking around in files: just run this once at the
> command line, and it will affect the current session and all future instances
> too.
>
> Or you can modify `$fish_user_paths` yourself, but you should be careful not
> to append to it unconditionally in config.fish, or it will grow longer and
> longer.
Deprecate more methods. Internal APIs have been verified to be unused
elsewhere and removed. External APIs have had deprecation methods added.
Existing deprecations have been either upgraded to produce warnings or
no longer deprecated and the reasoning documented.
