fix: make task failure errors include stack of running tasks (#2286)

Previously if a task was run as a dependency of another task,
the error message simply reported something like:

    exit status 1

It is desirable instead to name the root task and all child tasks in the tree
to the failing task.

After this PR, the error message will read:

    task: Failed to run task "root": task: Failed to run task "failing-task": exit status 1

task_test.go

@@ -569,7 +569,9 @@ func TestCyclicDep(t *testing.T) {
 		task.WithStderr(io.Discard),
 	)
 	require.NoError(t, e.Setup())
-	assert.IsType(t, &errors.TaskCalledTooManyTimesError{}, e.Run(t.Context(), &task.Call{Task: "task-1"}))
+	err := e.Run(t.Context(), &task.Call{Task: "task-1"})
+	var taskCalledTooManyTimesError *errors.TaskCalledTooManyTimesError
+	assert.ErrorAs(t, err, &taskCalledTooManyTimesError)
 }
 
 func TestTaskVersion(t *testing.T) {