toolchains: Expose raw JSON representation of a toolchain (#20721)

Closes #ISSUE

Release Notes:

- N/A

crates/languages/src/python.rs

@@ -591,8 +591,9 @@ impl ToolchainLister for PythonToolchainProvider {
                 .into();
                 Some(Toolchain {
                     name,
-                    path: toolchain.executable?.to_str()?.to_owned().into(),
+                    path: toolchain.executable.as_ref()?.to_str()?.to_owned().into(),
                     language_name: LanguageName::new("Python"),
+                    as_json: serde_json::to_value(toolchain).ok()?,
                 })
             })
             .collect();