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] <[email protected]>

Author: dependabot[bot]

requirements.txt

@@ -1,2 +1,2 @@
-ruamel.yaml >= 0.14.12, < 0.17.21
+ruamel.yaml >= 0.14.12, < 0.17.22
 schema-salad

setup.py

@@ -27,7 +27,7 @@
     package_data={"cwlupgrader.tests": ["../testdata/**/*.cwl"]},
     install_requires=[
         "setuptools",
-        "ruamel.yaml >= 0.14.12, < 0.17.21",
+        "ruamel.yaml >= 0.14.12, < 0.17.22",
         "schema_salad",
     ],
     entry_points={"console_scripts": ["cwl-upgrader = cwlupgrader.main:main"]},