Allow task context providers to access project env (#17964)

Closes #13106

Release Notes:

- Task context providers now have access to the local shell environment,
allowing local rust tool installations to work

Before:
<img width="1136" alt="Screenshot 2024-09-17 at 22 09 38"
src="https://github.com/user-attachments/assets/7d6c5606-4820-4f6f-92d1-c3d314b9ab42">

After:
<img width="1136" alt="Screenshot 2024-09-17 at 22 09 58"
src="https://github.com/user-attachments/assets/a962e607-15f5-44ce-b53e-a0dbe135f2d8">

crates/languages/src/go.rs

@@ -1,5 +1,6 @@
 use anyhow::{anyhow, Context, Result};
 use async_trait::async_trait;
+use collections::HashMap;
 use futures::StreamExt;
 use gpui::{AppContext, AsyncAppContext, Task};
 use http_client::github::latest_github_release;
@@ -454,6 +455,7 @@ impl ContextProvider for GoContextProvider {
         &self,
         variables: &TaskVariables,
         location: &Location,
+        _: Option<&HashMap<String, String>>,
         cx: &mut gpui::AppContext,
     ) -> Result<TaskVariables> {
         let local_abs_path = location