Bump tensorflow from 2.5.2 to 2.6.4

Bumps [tensorflow](https://github.com/tensorflow/tensorflow) from 2.5.2 to 2.6.4.
- [Release notes](https://github.com/tensorflow/tensorflow/releases)
- [Changelog](https://github.com/tensorflow/tensorflow/blob/master/RELEASE.md)
- [Commits](tensorflow/tensorflow@v2.5.2...v2.6.4)

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

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

Author: dependabot[bot]

requirementsALL.txt

@@ -49,7 +49,7 @@ six==1.15.0
 soupsieve==2.0.1
 sumeval==0.2.2
 sumy==0.8.1
-tensorflow==2.5.2
+tensorflow==2.6.4
 tqdm==4.48.2
 tweepy==3.9.0
 urllib3==1.26.5