Changed check in the pyright VS Code extension for the presence of Py…

…lance. If Pylance is installed in the workspace but is not configured to be loaded (i.e. the "python.languageServer" is set to "None"), then pyright will allow itself to be loaded. This addresses #9325.

packages/vscode-pyright/src/extension.ts

@@ -53,11 +53,14 @@ const pythonPathChangedListenerMap = new Map<string, string>();
 const defaultHeapSize = 3072;
 
 export async function activate(context: ExtensionContext) {
+    const pythonSettings = workspace.getConfiguration('python');
+    const langServer = pythonSettings.get('languageServer');
+
     // See if Pylance is installed. If so, don't activate the Pyright extension.
     // Doing so will generate "command already registered" errors and redundant
     // hover text, etc.because the two extensions overlap in functionality.
     const pylanceExtension = extensions.getExtension('ms-python.vscode-pylance');
-    if (pylanceExtension) {
+    if (pylanceExtension && langServer !== 'None') {
         window.showErrorMessage(
             'Pyright has detected that the Pylance extension is installed. ' +
                 'Pylance includes the functionality of Pyright, and running both of ' +