chore: add 'classic_parameter_flow' column setting to templates (#17828)

We are forcing users to try the dynamic parameter experience first.
Currently this setting only comes into effect if an experiment is
enabled.

coderd/database/dbmem/dbmem.go

@@ -11084,6 +11084,7 @@ func (q *FakeQuerier) UpdateTemplateMetaByID(_ context.Context, arg database.Upd
 		tpl.GroupACL = arg.GroupACL
 		tpl.AllowUserCancelWorkspaceJobs = arg.AllowUserCancelWorkspaceJobs
 		tpl.MaxPortSharingLevel = arg.MaxPortSharingLevel
+		tpl.UseClassicParameterFlow = arg.UseClassicParameterFlow
 		q.templates[idx] = tpl
 		return nil
 	}