fix: Fix ruamel import

[rushtehrani]

This PR fixes the following error when the ruamel.yaml version is greater than 0.11.4:

ModuleNotFoundError: No module named 'ruamel'

It also makes the code consistent with other code that uses this module.

[J-shang]

@rushtehrani Hi, thanks for your pr, but we don't meet this issue with ruamel.yaml == 0.16.12, could you show your ruamel.yaml version? Let's check if the version range of ruamel.yaml should be restricted.

And in some scenarios we will meet error using import ruamel.yaml as yaml, FYI.
#3276

[rushtehrani]

Hi @J-shang

@rushtehrani Hi, thanks for your pr, but we don't meet this issue with ruamel.yaml == 0.16.12, could you show your ruamel.yaml version? Let's check if the version range of ruamel.yaml should be restricted.

The version I was having issues with is 0.15.80, I think at some point they changed the name of the PyPi package from ruamel_yaml to ruamel.yaml.

And in some scenarios we will meet error using import ruamel.yaml as yaml, FYI.
#3276

Yes, I believe this is due to the name change in the most recent versions.

Note that import ruamel.yaml as yaml format is used in a few other places as well so I think #3276 might be an issue there too?

[J-shang]

@rushtehrani Hi, you are right, I find the doc https://yaml.readthedocs.io/en/latest/api.html , and this pr will be merged. Thanks for your contribution and if there is any other issue, welcome to communicate with us.