Thanks for getting in touch! I had a look into this and I believe I've found the issue. Your log file states that the your server has PowerShell v1 and v2 on it and .NET v2 on it (CLR version). I did some digging and found that the Sql Server 2012 SDK assemblies require .NET v4 and thus you also need PowerShell v3 or newer as well. I'd recommend upgrading your server so you can take advantage of the DACPAC community step.
It looks like this issue could be a couple of things. The script is failing when PowerShell adds the following DLL's and tries to load the DAC assemblies and fails.
02:47:30 Verbose | Adding the type: C:\Program Files\Microsoft SQL Server\140\DAC\bin\Microsoft.SqlServer.TransactSql.ScriptDom.dll
02:47:30 Verbose | Adding the type: C:\Program Files\Microsoft SQL Server\140\DAC\bin\Microsoft.SqlServer.Dac.dll
02:47:30 Info | Loaded the DAC assemblies
02:47:30 Error | Deployment failed: Exception calling "Load" with "1" argument(s): "The type
02:47:30 Error | initializer for 'Microsoft.SqlServer.Dac.DacPackage' threw an exception."
02:47:30 Error | Reason: The type initializer for 'Microsoft.SqlServer.Dac.DacPackage' threw an
02:47:30 Error | exception.
I did a search online and found a few different possible causes. You will need to determine which one is relevant based on your environment and not Octopus by the looks of it.
I did some looking into this and from what I can see this could be related to your sqlproj being aimed at the wrong sql version. The following conversation seems to have the same error that you are now seeing and included how they troubleshooted this issue.