debugger: Fix the JavaScript debug terminal scenario (#33924)

There were a couple of things preventing this from working:

- our hack to stop the node REPL from appearing broke in recent versions
of the JS DAP that started passing `--experimental-network-inspection`
by default
- we had lost the ability to create a debug terminal without specifying
a program

This PR fixes those issues. We also fixed environment variables from the
**runInTerminal** request not getting passed to the spawned program.

Release Notes:

- Debugger: Fix RunInTerminal not working for JavaScript debugger.

---------

Co-authored-by: Cole Miller <cole@zed.dev>

crates/assistant_tools/src/terminal_tool.rs

@@ -218,7 +218,7 @@ impl Tool for TerminalTool {
                     .update(cx, |project, cx| {
                         project.create_terminal(
                             TerminalKind::Task(task::SpawnInTerminal {
-                                command: program,
+                                command: Some(program),
                                 args,
                                 cwd,
                                 env,