Bump pillow from 4.3.0 to 9.0.0

Bumps [pillow](https://github.com/python-pillow/Pillow) from 4.3.0 to 9.0.0.
- [Release notes](https://github.com/python-pillow/Pillow/releases)
- [Changelog](https://github.com/python-pillow/Pillow/blob/main/CHANGES.rst)
- [Commits](python-pillow/Pillow@4.3.0...9.0.0)

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

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

Author: dependabot[bot]

requirements.txt

@@ -10,7 +10,7 @@ moviepy==0.2.3.2
 nltk==3.2.5
 numpy==1.13.3
 olefile==0.44
-Pillow==4.3.0
+Pillow==9.0.0
 pysrt==1.1.1
 pytube==6.4.2
 requests==2.18.4