fix: correct uv task test assertions

Agent-Logs-Url: https://github.com/microsoft/vscode-python-environments/sessions/5f628821-9c7b-48a6-9f5f-9fccb9a33bf6

Co-authored-by: eleanorjboyd <26030610+eleanorjboyd@users.noreply.github.com>

Author: Copilot

src/test/features/execution/runAsTask.unit.test.ts

@@ -154,6 +154,7 @@ suite('runAsTask Tests', () => {
 
             assert.strictEqual(result, mockTaskExecution, 'Should return the task execution result');
 
+            const taskArg = mockExecuteTask.firstCall.args[0] as Task;
             const execution = taskArg.execution as ShellExecution;
 
             assert.strictEqual(execution.command, 'uv', 'Should execute uv when uv mode is enabled');
@@ -201,7 +202,6 @@ suite('runAsTask Tests', () => {
 
             await runAsTask(environment, options);
 
-            const taskArg = mockExecuteTask.firstCall.args[0] as Task;
             const execution = taskArg.execution as ShellExecution;
 
             assert.strictEqual(execution.command, '"uv"', 'Should quote the uv executable when required');