Allow env variable in while configuring mcp in config toml

What feature would you like to see?

as of Today you can't do something like this

[mcp_servers.test]
command = "uvx"
args = ["--from", "/path/test-mcp", "test-mcp"]
env = {USER = "bot",  PASSWORD = "$BOT_PASSWORD"}

What works today is cmd like override like this which is not great if user has quite few such mcp the cmd line explode.

--config 'mcp_servers.test.env.BOT_PASSWORD="'"$BOT_PASSWORD"'"'

Additional information

_No response_