pylsp: Upgrade existing installation if possible (#28338)

Closes #ISSUE

Release Notes:

- Zed-managed pylsp installations will now correctly upgrade themselves

crates/languages/src/python.rs

@@ -991,6 +991,7 @@ impl LspAdapter for PyLspAdapter {
             util::command::new_smol_command(pip_path.as_path())
                 .arg("install")
                 .arg("python-lsp-server")
+                .arg("-U")
                 .output()
                 .await?
                 .status
@@ -1001,6 +1002,7 @@ impl LspAdapter for PyLspAdapter {
             util::command::new_smol_command(pip_path.as_path())
                 .arg("install")
                 .arg("python-lsp-server[all]")
+                .arg("-U")
                 .output()
                 .await?
                 .status
@@ -1011,6 +1013,7 @@ impl LspAdapter for PyLspAdapter {
             util::command::new_smol_command(pip_path)
                 .arg("install")
                 .arg("pylsp-mypy")
+                .arg("-U")
                 .output()
                 .await?
                 .status