Upgrade lightning version to fix vulnerability issue (facebookresearc…

…h#15)

Summary:
Pull Request resolved: facebookresearch#15

One of FLAVA example module's dependencies -- pytorch_lightning version 1.5.10 --- is being identified for vulnerability issue by GitHub (see GHSA-r5qj-cvf9-p85h).
This is fixed in v 1.6.0 -- Lightning-AI/pytorch-lightning@8b7a12c
This has triggered a high priority task for the oncall.

Test Plan: Merge the PR and run OSS autocheck again. The issue should be gone by then.

Reviewed By: ankitade

Differential Revision: D35445752

Pulled By: langong347

fbshipit-source-id: 61b0cca3c2f1af590835b50da1834a07ab0b2bfd

examples/flava/requirements.txt

@@ -1,5 +1,5 @@
 Pillow==9.0.1
-pytorch-lightning==1.5.10
+pytorch-lightning==1.6.0
 datasets==2.0.0
 requests==2.27.1
 DALL-E==0.1