Fix lang servers status set to Downloading when checking version (#22292)

This message has confused me many times too: we printed the status as
"Downloading" when we were only checking whether we need to install a
given version of a language server.

This fixes the issue for Node-based language servers where we had the
same check in all implementations.

Closes  #22241

Release Notes:

- Fixed some language servers reporting status as "Downloading..." when
only a version check was being done.

crates/languages/src/css.rs

@@ -26,6 +26,7 @@ pub struct CssLspAdapter {
 }
 
 impl CssLspAdapter {
+    const PACKAGE_NAME: &str = "vscode-langservers-extracted";
     pub fn new(node: NodeRuntime) -> Self {
         CssLspAdapter { node }
     }
@@ -56,18 +57,13 @@ impl LspAdapter for CssLspAdapter {
     ) -> Result<LanguageServerBinary> {
         let latest_version = latest_version.downcast::<String>().unwrap();
         let server_path = container_dir.join(SERVER_PATH);
-        let package_name = "vscode-langservers-extracted";
 
-        let should_install_language_server = self
-            .node
-            .should_install_npm_package(package_name, &server_path, &container_dir, &latest_version)
-            .await;
-
-        if should_install_language_server {
-            self.node
-                .npm_install_packages(&container_dir, &[(package_name, latest_version.as_str())])
-                .await?;
-        }
+        self.node
+            .npm_install_packages(
+                &container_dir,
+                &[(Self::PACKAGE_NAME, latest_version.as_str())],
+            )
+            .await?;
 
         Ok(LanguageServerBinary {
             path: self.node.binary_path().await?,
@@ -76,6 +72,31 @@ impl LspAdapter for CssLspAdapter {
         })
     }
 
+    async fn check_if_version_installed(
+        &self,
+        version: &(dyn 'static + Send + Any),
+        container_dir: &PathBuf,
+        _: &dyn LspAdapterDelegate,
+    ) -> Option<LanguageServerBinary> {
+        let version = version.downcast_ref::<String>().unwrap();
+        let server_path = container_dir.join(SERVER_PATH);
+
+        let should_install_language_server = self
+            .node
+            .should_install_npm_package(Self::PACKAGE_NAME, &server_path, &container_dir, &version)
+            .await;
+
+        if should_install_language_server {
+            None
+        } else {
+            Some(LanguageServerBinary {
+                path: self.node.binary_path().await.ok()?,
+                env: None,
+                arguments: server_binary_arguments(&server_path),
+            })
+        }
+    }
+
     async fn cached_server_binary(
         &self,
         container_dir: PathBuf,