ssh project: Handle multiple paths and worktrees correctly (#18277)

This makes SSH projects work with `ssh_connections` that have multiple
paths:

```json
{
  "ssh_connections": [
    {
      "host": "127.0.0.1",
      "projects": [
        {
          "paths": [
            "/Users/thorstenball/work/projs/go-proj",
            "/Users/thorstenball/work/projs/rust-proj"
          ]
        }
      ]
    }
  ]
}
```

@ConradIrwin @mikayla-maki since this wasn't really released yet, we
didn't create a full-on migration, so old ssh projects that were already
serialized need to either be manually deleted from the database, or the
whole local DB wiped.

Release Notes:

- N/A

---------

Co-authored-by: Bennet <bennet@zed.dev>

crates/workspace/src/workspace.rs

@@ -5516,14 +5516,14 @@ pub fn open_ssh_project(
     cx: &mut AppContext,
 ) -> Task<Result<()>> {
     cx.spawn(|mut cx| async move {
-        // TODO: Handle multiple paths
-        let path = paths.iter().next().cloned().unwrap_or_default();
-
         let serialized_ssh_project = persistence::DB
             .get_or_create_ssh_project(
                 connection_options.host.clone(),
                 connection_options.port,
-                path.to_string_lossy().to_string(),
+                paths
+                    .iter()
+                    .map(|path| path.to_string_lossy().to_string())
+                    .collect::<Vec<_>>(),
                 connection_options.username.clone(),
             )
             .await?;