Update ruamel-yaml requirement

Updates the requirements on [ruamel-yaml](https://sourceforge.net/p/ruamel-yaml/code/ci/default/tree) to permit the latest version.

---
updated-dependencies:
- dependency-name: ruamel-yaml
  dependency-type: direct:production
...

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

Author: dependabot[bot]

setup.py

@@ -28,7 +28,7 @@
     include_package_data=True,
     install_requires=[
         "connexion >= 2.0.2, < 3",
-        "ruamel.yaml >= 0.15.78, <= 0.16.5",
+        "ruamel.yaml >= 0.15.78, < 0.17.11",
         "schema-salad",
     ],
     entry_points={