Update ruamel-yaml requirement from <0.18,>=0.17.6 to >=0.17.6,<0.19

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>

requirements.txt

@@ -4,4 +4,4 @@ rdflib
 requests
 schema-salad >= 8.3.20220825114525, < 9
 ruamel.yaml >= 0.17.6, < 0.18;python_version>='3.7'
-ruamel.yaml >= 0.16.12, < 0.18
+ruamel.yaml >= 0.16.12, < 0.19