Update active transferwise variants to point to the corresponding subdirectories in transferwise/pipelinewise

[edgarrmondragon]

To better serve Wise business and customer needs, the PipelineWise codebase needs to shrink. We have made the difficult decision that, going forward many components of PipelineWise will be removed or incorporated in the main repo.

On Slack:

• https://meltano.slack.com/archives/C069A0GE129/p1730907152827889

[edgarrmondragon]

Example from Slack:

  name: target-postgres
- pip_url: pipelinewise-target-postgres
+ pip_url: git+https://github.com/transferwise/pipelinewise.git#subdirectory=singer-connectors/target-postgres
- repo: https://github.com/transferwise/pipelinewise-target-postgres
+ repo: https://github.com/transferwise/pipelinewise
  variant: transferwise