Default DataLoader shuffle=True for training (#5623)

* Fix shuffle DataLoader argument

* Add shuffle argument

* Disable shuffle when rect

* Cleanup, add rect warning

* [pre-commit.ci] auto fixes from pre-commit.com hooks

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* Cleanup2

* Cleanup3

Co-authored-by: Glenn Jocher <glenn.jocher@ultralytics.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

train.py

@@ -212,7 +212,7 @@ def train(hyp,  # path/to/hyp.yaml or hyp dictionary
     train_loader, dataset = create_dataloader(train_path, imgsz, batch_size // WORLD_SIZE, gs, single_cls,
                                               hyp=hyp, augment=True, cache=opt.cache, rect=opt.rect, rank=LOCAL_RANK,
                                               workers=workers, image_weights=opt.image_weights, quad=opt.quad,
-                                              prefix=colorstr('train: '))
+                                              prefix=colorstr('train: '), shuffle=True)
     mlc = int(np.concatenate(dataset.labels, 0)[:, 0].max())  # max label class
     nb = len(train_loader)  # number of batches
     assert mlc < nc, f'Label class {mlc} exceeds nc={nc} in {data}. Possible class labels are 0-{nc - 1}'