Remove issuer_name="PyPI" default kwarg (#5887)
Remove issuer_name="PyPI" default kwarg (#5887)

Remove an unnecessary and confusing kwarg in
`generate_totp_provisioning_uri`. This value should always come from the
`site.name` configuration value instead, and that value should always be set.
pypa/warehouse,pypa/warehouse,pypa/warehouse,pypa/warehouse