Azure stores a createdTime and changedTime property on all resources that you can query by adding the $expand parameter to the URL.
The expand parameter isn't documented in the Resource Groups API docs, but it is documented in the List Resources API docs (https://learn.microsoft.com/en-us/rest/api/resources/resources/list) and it works the same way.
I don't know offhand how to add this parameter using the Python API, but here is an example of the REST API itself (using the Try It button from the docs at https://learn.microsoft.com/en-us/rest/api/resources/resourcegroups/list#code-try-0).
GET https://management.azure.com/subscriptions/1237f4d2-3dce-4b96-ad95-677f764e7123/resourcegroups?api-version=2019-08-01&%24expand=createdTime
{
"value": [
{
"id": "/subscriptions/1237f4d2-3dce-4b96-ad95-677f764e7123/resourceGroups/test2rg-3-backup",
"name": "test2rg-3-backup",
"type": "Microsoft.Resources/resourceGroups",
"location": "eastus",
"createdTime": "2018-11-12T18:08:38.667582Z",
"properties": {
"provisioningState": "Succeeded"
}
},
{
"id": "/subscriptions/1237f4d2-3dce-4b96-ad95-677f764e7123/resourceGroups/proddeploy",
"name": "proddeploy",
"type": "Microsoft.Resources/resourceGroups",
"location": "eastus",
"createdTime": "2019-01-10T21:28:48.8057057Z",
"tags": {
"a": "b"
},
"properties": {
"provisioningState": "Succeeded"
}
},
...