languages: Remove broken pixi environment activation (#37915)

Closes [#ISSUE](https://github.com/zed-industries/zed/issues/37895)

This needs more thought behind it to be implemented properly

Release Notes:

- N/A

crates/languages/src/python.rs

@@ -892,10 +892,6 @@ impl ToolchainLister for PythonToolchainProvider {
         let mut activation_script = vec![];
 
         match toolchain.kind {
-            Some(PythonEnvironmentKind::Pixi) => {
-                let env = toolchain.name.as_deref().unwrap_or("default");
-                activation_script.push(format!("pixi shell -e {env}"))
-            }
             Some(PythonEnvironmentKind::Conda) => {
                 if let Some(name) = &toolchain.name {
                     activation_script.push(format!("conda activate {name}"));