Bump tensorflow from 2.8.0 to 2.8.1

Bumps [tensorflow](https://github.com/tensorflow/tensorflow) from 2.8.0 to 2.8.1.
- [Release notes](https://github.com/tensorflow/tensorflow/releases)
- [Changelog](https://github.com/tensorflow/tensorflow/blob/master/RELEASE.md)
- [Commits](tensorflow/tensorflow@v2.8.0...v2.8.1)

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

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

doc/requirements.txt

@@ -17,7 +17,7 @@ sphinx-autodoc-typehints==1.10.3
 sphinx-copybutton==0.4.0
 sphinx-automodapi==0.13
 sphinxcontrib-bibtex==0.4.2
-tensorflow==2.6.3
+tensorflow==2.8.1
 thewalrus==0.18.0
 toml==0.10.2
 xanadu-sphinx-theme==0.1.0

requirements.txt

@@ -7,7 +7,7 @@ quantum-blackbird==0.4.0
 requests==2.27.1
 scipy==1.8.0
 sympy==1.10
-tensorflow==2.8.0
+tensorflow==2.8.1
 tensorboard==2.8.0
 thewalrus==0.19.0
 toml==0.10.2