The credentials are created with
`az ad sp create-for-rbac --name "playwright-github-actions" --role
"Storage Blob Data Contributor" --scopes /subscriptions/<subscription
id>/resourceGroups/<resource
group>/providers/Microsoft.Storage/storageAccounts/<storage account>`
We cannot use `azure/login@v1` for login as it does not see to properly
propagate credentials to `azcopy` in the next step (there are some
reports about keyring problems on linux based actions).
Also:
- remove `blob-report` directory at the start;
- markdown's `report.md` next to package.json;
- use default location in playwright's workflows.
References #24451.
