build(deps): bump tensorflow in /Traffic-Sign-Detection

Bumps [tensorflow](https://github.com/tensorflow/tensorflow) from 2.5.3 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@v2.5.3...v2.6.4)

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

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

Author: dependabot[bot]

Traffic-Sign-Detection/requirements.txt

@@ -104,7 +104,7 @@ six==1.15.0
 SoundFile==0.10.3.post1
 tensorboard==2.4.1
 tensorboard-plugin-wit==1.7.0
-tensorflow==2.5.3
+tensorflow==2.6.4
 tensorflow-estimator==2.4.0
 tensorflow-gpu==2.5.3
 termcolor==1.1.0