docs: update links to 1.6 1.5 1.4 (#17181)

(cherry picked from commit 32a6d2f)

Author: Borda

docs/source-pytorch/past_versions.rst

@@ -46,42 +46,42 @@ TO help you with keeping up to spead, check :doc:`Migration guide <./upgrade/mig
      - :doc:`from 1.7 to 2.0 <upgrade/from_1_7>`
 
    * - `1.6 <https://github.com/Lightning-AI/lightning/releases/tag/1.6.0>`_
-     - `Support Intel's Habana Accelerator, New efficient DDP strategy (Bagua), Manual Fault-tolerance, Stability and Reliability <https://pytorch-lightning.readthedocs.io/en/1.6.5>`_
-     - `1.6.0 <https://pytorch-lightning.readthedocs.io/en/1.6.0>`_,
-       `1.6.1 <https://pytorch-lightning.readthedocs.io/en/1.6.1>`_,
-       `1.6.2 <https://pytorch-lightning.readthedocs.io/en/1.6.2>`_,
-       `1.6.3 <https://pytorch-lightning.readthedocs.io/en/1.6.3>`_,
-       `1.6.4 <https://pytorch-lightning.readthedocs.io/en/1.6.4>`_,
-       `1.6.5 <https://pytorch-lightning.readthedocs.io/en/1.6.5>`_
+     - `Support Intel's Habana Accelerator, New efficient DDP strategy (Bagua), Manual Fault-tolerance, Stability and Reliability <https://lightning.ai/docs/pytorch/1.6.5>`_
+     - `1.6.0 <https://lightning.ai/docs/pytorch/1.6.0>`_,
+       `1.6.1 <https://lightning.ai/docs/pytorch/1.6.1>`_,
+       `1.6.2 <https://lightning.ai/docs/pytorch/1.6.2>`_,
+       `1.6.3 <https://lightning.ai/docs/pytorch/1.6.3>`_,
+       `1.6.4 <https://lightning.ai/docs/pytorch/1.6.4>`_,
+       `1.6.5 <https://lightning.ai/docs/pytorch/1.6.5>`_
      - :doc:`from 1.6 to 2.0 <upgrade/from_1_6>`
 
    * - `1.5 <https://github.com/Lightning-AI/lightning/releases/tag/1.5.0>`_
-     - `LightningLite, Fault-Tolerant Training, Loop Customization, Lightning Tutorials, LightningCLI v2, RichProgressBar, CheckpointIO Plugin, and Trainer Strategy Flag <https://pytorch-lightning.readthedocs.io/en/1.5.10>`_
-     - `1.5.0 <https://pytorch-lightning.readthedocs.io/en/1.5.0>`_,
-       `1.5.1 <https://pytorch-lightning.readthedocs.io/en/1.5.1>`_,
-       `1.5.2 <https://pytorch-lightning.readthedocs.io/en/1.5.2>`_,
-       `1.5.3 <https://pytorch-lightning.readthedocs.io/en/1.5.3>`_,
-       `1.5.4 <https://pytorch-lightning.readthedocs.io/en/1.5.4>`_,
-       `1.5.5 <https://pytorch-lightning.readthedocs.io/en/1.5.5>`_,
-       `1.5.6 <https://pytorch-lightning.readthedocs.io/en/1.5.6>`_,
-       `1.5.7 <https://pytorch-lightning.readthedocs.io/en/1.5.7>`_,
-       `1.5.8 <https://pytorch-lightning.readthedocs.io/en/1.5.8>`_,
-       `1.5.9 <https://pytorch-lightning.readthedocs.io/en/1.5.9>`_,
-       `1.5.10 <https://pytorch-lightning.readthedocs.io/en/1.5.10>`_
+     - `LightningLite, Fault-Tolerant Training, Loop Customization, Lightning Tutorials, LightningCLI v2, RichProgressBar, CheckpointIO Plugin, and Trainer Strategy Flag <https://lightning.ai/docs/pytorch/1.5.10>`_
+     - `1.5.0 <https://lightning.ai/docs/pytorch/1.5.0>`_,
+       `1.5.1 <https://lightning.ai/docs/pytorch/1.5.1>`_,
+       `1.5.2 <https://lightning.ai/docs/pytorch/1.5.2>`_,
+       `1.5.3 <https://lightning.ai/docs/pytorch/1.5.3>`_,
+       `1.5.4 <https://lightning.ai/docs/pytorch/1.5.4>`_,
+       `1.5.5 <https://lightning.ai/docs/pytorch/1.5.5>`_,
+       `1.5.6 <https://lightning.ai/docs/pytorch/1.5.6>`_,
+       `1.5.7 <https://lightning.ai/docs/pytorch/1.5.7>`_,
+       `1.5.8 <https://lightning.ai/docs/pytorch/1.5.8>`_,
+       `1.5.9 <https://lightning.ai/docs/pytorch/1.5.9>`_,
+       `1.5.10 <https://lightning.ai/docs/pytorch/1.5.10>`_
      - :doc:`from 1.5 to 2.0 <upgrade/from_1_5>`
 
    * - `1.4 <https://github.com/Lightning-AI/lightning/releases/tag/1.4.0>`_
-     - `TPU Pod Training, IPU Accelerator, DeepSpeed Infinity, Fully Sharded Data Parallel <https://pytorch-lightning.readthedocs.io/en/1.4.9>`_
-     - `1.4.0 <https://pytorch-lightning.readthedocs.io/en/1.4.0>`_,
-       `1.4.1 <https://pytorch-lightning.readthedocs.io/en/1.4.1>`_,
-       `1.4.2 <https://pytorch-lightning.readthedocs.io/en/1.4.2>`_,
-       `1.4.3 <https://pytorch-lightning.readthedocs.io/en/1.4.3>`_,
-       `1.4.4 <https://pytorch-lightning.readthedocs.io/en/1.4.4>`_,
-       `1.4.5 <https://pytorch-lightning.readthedocs.io/en/1.4.5>`_,
-       `1.4.6 <https://pytorch-lightning.readthedocs.io/en/1.4.6>`_,
-       `1.4.7 <https://pytorch-lightning.readthedocs.io/en/1.4.7>`_,
-       `1.4.8 <https://pytorch-lightning.readthedocs.io/en/1.4.8>`_,
-       `1.4.9 <https://pytorch-lightning.readthedocs.io/en/1.4.9>`_
+     - `TPU Pod Training, IPU Accelerator, DeepSpeed Infinity, Fully Sharded Data Parallel <https://lightning.ai/docs/pytorch/1.4.9>`_
+     - `1.4.0 <https://lightning.ai/docs/pytorch/1.4.0>`_,
+       `1.4.1 <https://lightning.ai/docs/pytorch/1.4.1>`_,
+       `1.4.2 <https://lightning.ai/docs/pytorch/1.4.2>`_,
+       `1.4.3 <https://lightning.ai/docs/pytorch/1.4.3>`_,
+       `1.4.4 <https://lightning.ai/docs/pytorch/1.4.4>`_,
+       `1.4.5 <https://lightning.ai/docs/pytorch/1.4.5>`_,
+       `1.4.6 <https://lightning.ai/docs/pytorch/1.4.6>`_,
+       `1.4.7 <https://lightning.ai/docs/pytorch/1.4.7>`_,
+       `1.4.8 <https://lightning.ai/docs/pytorch/1.4.8>`_,
+       `1.4.9 <https://lightning.ai/docs/pytorch/1.4.9>`_
      - :doc:`from 1.4 to 2.0 <upgrade/from_1_4>`
 
    * - `1.3 <https://github.com/Lightning-AI/lightning/releases/tag/1.3.0>`_