chore(deps-dev): update tensorflow requirement

Updates the requirements on [tensorflow](https://github.com/tensorflow/tensorflow) to permit the latest version.
- [Release notes](https://github.com/tensorflow/tensorflow/releases)
- [Changelog](https://github.com/tensorflow/tensorflow/blob/master/RELEASE.md)
- [Commits](tensorflow/tensorflow@v2.5.0...v2.18.0)

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

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

Author: dependabot[bot]

setup.cfg

@@ -69,7 +69,7 @@ neural_tangents =
     jax <= 0.2.12
     neural_tangents < 0.6.0
 gpflow =
-    tensorflow >= 2.5, < 2.9
+    tensorflow >= 2.5, < 2.19
     tensorflow-probability >= 0.12, < 0.13
     gpflow >= 2.2.0, < 2.6.0
 botorch =
@@ -82,7 +82,7 @@ all =
     jaxlib <= 0.1.65
     jax <= 0.2.12
     neural_tangents < 0.6.0
-    tensorflow >= 2.5, < 2.9
+    tensorflow >= 2.5, < 2.19
     tensorflow-probability >= 0.12, < 0.13
     gpflow >= 2.2.0, < 2.6.0
     torch