Bump tensorflow from 2.4.0 to 2.5.0 in /tests (#633)

Bumps [tensorflow](https://github.com/tensorflow/tensorflow) from 2.4.0 to 2.5.0.
- [Release notes](https://github.com/tensorflow/tensorflow/releases)
- [Changelog](https://github.com/tensorflow/tensorflow/blob/master/RELEASE.md)
- [Commits](tensorflow/tensorflow@v2.4.0...v2.5.0)

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tests/requirements.txt

@@ -2,7 +2,7 @@ torch==1.4.0
 torchvision==0.5.0
 jaxlib==0.1.46
 jax==0.1.66
-tensorflow==2.4.0
+tensorflow==2.5.0
 numba==0.50.1
 matplotlib==3.2.1
 pillow==8.1.1