The Solution is to use the new CMDlet "Restore-AzSynapseSqlPool"
Synapse dedicated SQLPool Backup cannot be restored

We are trying to restore a deleted SQL dedicated pool.
By using the statement Get-AzSqlDeletedDatabaseBackup. We can see the database that we are trying to restore.
Then we are using the Statement Restore-AzSqlDatabse to restore it. But we get the error that we have the permission to 'Microsoft.Sql/servers/databases/write', however do not have the permission to perform action "read" on the "0" lined scope "". It is blocked by deny assignements.
What the error is telling us - we could restore to the targetserver but we are not allowed to read from the autogenerated SynapseWorkspace Resource Group since Microsoft placed a denyassignment on this.
PLEASE Do net provide me the article you can find below since we are excatly doing this stuff and are having the issues because Synapse Workspace unfortunatley runs diffrently then the former dedicated pools.