Bump pillow from 7.0.0 to 8.3.2 in /LAB03/04-Xray/backend

Bumps [pillow](https://github.com/python-pillow/Pillow) from 7.0.0 to 8.3.2.
- [Release notes](https://github.com/python-pillow/Pillow/releases)
- [Changelog](https://github.com/python-pillow/Pillow/blob/master/CHANGES.rst)
- [Commits](python-pillow/Pillow@7.0.0...8.3.2)

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

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

LAB03/04-Xray/backend/requirements.txt

@@ -12,7 +12,7 @@ flask-restplus==0.13.0
 bson==0.5.8
 Flask-JWT-Extended==3.24.1
 Flask-Bcrypt==0.7.1
-Pillow==7.0.0
+Pillow==8.3.2
 pynamodb==4.3.1
 tzlocal==2.0.0
 boto3==1.11.13