Relates to https://github.com/coder/coder/issues/15390
Currently when a user creates a workspace, their workspace's TTL is
determined by the template's default TTL. If the Coder instance is AGPL,
or if the template has disallowed the user from configuring autostop,
then it is not possible to change the workspace's TTL after creation.
Any changes to the template's default TTL only takes effect on _new_
workspaces.
This PR modifies the behaviour slightly so that on AGPL Coder, or on
enterprise when a template does not allow user's to configure their
workspace's TTL, updating the template's default TTL will also update
any workspace's TTL to match this value.
40624bf78b