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]

requirements.txt

@@ -1,5 +1,5 @@
 ruamel.yaml >= 0.16.0, < 0.17.27;python_version>='3.10'
 ruamel.yaml >= 0.15.98, < 0.17.27;python_version>='3.9'
 ruamel.yaml >= 0.15.78, < 0.17.27;python_version>='3.8'
-ruamel.yaml >= 0.15.71, < 0.17.27
+ruamel.yaml >= 0.15.71, < 0.17.28
 schema-salad

setup.py

@@ -30,7 +30,7 @@
         "ruamel.yaml >= 0.16.0, < 0.17.27;python_version>='3.10'",
         "ruamel.yaml >= 0.15.98, < 0.17.27;python_version>='3.9'",
         "ruamel.yaml >= 0.15.78, < 0.17.27;python_version>='3.8'",
-        "ruamel.yaml >= 0.15.71, < 0.17.27",
+        "ruamel.yaml >= 0.15.71, < 0.17.28",
         "schema_salad",
     ],
     entry_points={"console_scripts": ["cwl-upgrader = cwlupgrader.main:main"]},