Fix small errors preventing WSL support from working (#37350)

On nightly, when I run `zed` under WSL, I get an error parsing the
shebang line

```
/usr/bin/env: ‘sh\r’: No such file or directory
```

I believe that this is because in CI, Git checks out the file with CRLF
line endings, and that is how it is copied into the installer.

Also, the file extension was incorrect when downloading the production
remote server (a gzipped binary), preventing extraction from working
properly.

Release Notes:

- N/A

.gitattributes

@@ -1,2 +1,5 @@
 # Prevent GitHub from displaying comments within JSON files as errors.
 *.json linguist-language=JSON-with-Comments
+
+# Ensure the WSL script always has LF line endings, even on Windows
+crates/zed/resources/windows/zed-wsl text eol=lf