Bump pillow from 8.3.2 to 9.3.0 in /ICLR2023

Bumps [pillow](https://github.com/python-pillow/Pillow) from 8.3.2 to 9.3.0.
- [Release notes](https://github.com/python-pillow/Pillow/releases)
- [Changelog](https://github.com/python-pillow/Pillow/blob/main/CHANGES.rst)
- [Commits](python-pillow/Pillow@8.3.2...9.3.0)

---
updated-dependencies:
- dependency-name: pillow
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

ICLR2023/requirements.txt

@@ -158,7 +158,7 @@ Pebble==4.6.3
 petname==2.6
 pexpect==4.8.0
 pickleshare==0.7.5
-Pillow==8.3.2
+Pillow==9.3.0
 platformdirs==2.3.0
 portalocker==1.7.1
 preshed==3.0.5