`allowScimProvisioning` is cached with the domain as DOMAIN_FLAG_SCIM, but
it wasn't among the fields whose change drops the cached entry, so flipping
the flag changed nothing until something else evicted the domain. SCIM-60
says the change takes effect without a restart.
Found by the two acceptance checks that were written but never called from
the driver, so neither had ever run: `authority` (SCIM-58 to SCIM-60,
through `synchronize_account` itself) and `rate_limits` (SCIM-14). Both are
wired in now, and `scim_tests` passes with them.
jcoffey-dev
5cc28784df