cli: Null stdio handles when spawning Zed on Windows (#52583)

Self-Review Checklist:

- [x] I've reviewed my own diff for quality, security, and reliability
- [ ] Unsafe blocks (if any) have justifying comments
- [x] The content is consistent with the [UI/UX
checklist](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)
- [ ] Tests cover the new/changed behavior
- [x] Performance impact has been considered and is acceptable

Closes #51101

Release Notes:

- Fixed issue where launching Zed from Git Bash would leave the Ctrl
modifier stuck in the terminal.

## Demo

### Before:


https://github.com/user-attachments/assets/301c73a0-768b-437d-8a88-88d7db320c15

### After:



https://github.com/user-attachments/assets/2ec75f5e-16b9-4551-86d9-d59447712e7a

crates/cli/src/main.rs

@@ -1101,7 +1101,7 @@ mod windows {
     use crate::{Detect, InstalledApp};
     use std::io;
     use std::path::{Path, PathBuf};
-    use std::process::ExitStatus;
+    use std::process::{ExitStatus, Stdio};
 
     fn check_single_instance() -> bool {
         let mutex = unsafe {
@@ -1144,6 +1144,9 @@ mod windows {
                 if let Some(dir) = user_data_dir {
                     cmd.arg("--user-data-dir").arg(dir);
                 }
+                cmd.stdin(Stdio::null())
+                    .stdout(Stdio::null())
+                    .stderr(Stdio::null());
                 cmd.spawn()?;
             } else {
                 unsafe {