Bump tensorflow from 2.6.1 to 2.6.3 (#680)

Bumps [tensorflow](https://github.com/tensorflow/tensorflow) from 2.6.1 to 2.6.3.
- [Release notes](https://github.com/tensorflow/tensorflow/releases)
- [Changelog](https://github.com/tensorflow/tensorflow/blob/master/RELEASE.md)
- [Commits](tensorflow/tensorflow@v2.6.1...v2.6.3)

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

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

doc/requirements.txt

@@ -15,7 +15,7 @@ sphinx-autodoc-typehints==1.10.3
 sphinx-copybutton==0.4.0
 sphinx-automodapi==0.13
 sphinxcontrib-bibtex==0.4.2
-tensorflow==2.6.1
+tensorflow==2.6.3
 thewalrus==0.18.0
 toml==0.10.2
 mistune==0.8.4

requirements.txt

@@ -8,7 +8,7 @@ quantum-blackbird==0.4.0
 requests==2.22.0
 scipy==1.7.1
 sympy==1.8
-tensorflow==2.6.1
+tensorflow==2.6.3
 tensorboard==2.6.0
 thewalrus==0.18.0
 toml==0.10.2