Fix duplicated venv prompt (microsoft/vscode-python#23201)

Resolves: microsoft/vscode-python#23193 microsoft/vscode-python#23184

Resolve duplicated (.venv) prompt for users terminal.
Issue came from: microsoft/vscode-python#23080

extensions/positron-python/src/client/terminals/envCollectionActivation/service.ts

@@ -468,7 +468,7 @@ function getPromptForEnv(interpreter: PythonEnvironment | undefined, env: Enviro
             return undefined;
         }
         if (interpreter.type === PythonEnvType.Virtual && env.VIRTUAL_ENV_PROMPT) {
-            return `(${env.VIRTUAL_ENV_PROMPT}) `;
+            return `${env.VIRTUAL_ENV_PROMPT}`;
         }
         return `(${interpreter.envName}) `;
     }