docs: fix pytorch version typo in upgrade/from_2_0 (Lightning-AI#20333)

Author: wujian752

docs/source-pytorch/upgrade/sections/2_0_regular.rst

@@ -6,7 +6,7 @@
      - Then
      - Ref
 
-   * - used PyTorch 3.11
+   * - used PyTorch 1.11
      - upgrade to PyTorch 2.1 or higher
      - `PR18691`_