deps: increase pyyaml upper limit

[chenrui333]

• similar to https://github.com/aws/aws-cli/pull/8037
• https://github.com/yaml/pyyaml/pull/702 (pyyaml 6.0.1 pin cython < 3.0)

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[kddejong]

Already increased