Switch ambient DAP flows to WebSockets transport

What does this MR do and why?

Switch aminent DAP flows to WebSockets transport

In order to unify architecture around sigle transport layer used for all enviroments of DAP, ambient environment switches to WebSockets

References

• https://gitlab.com/gitlab-org/gitlab/-/issues/578048#note_2899259404
• gitlab-org/editor-extensions/gitlab-lsp!2489 (comment 2898392380)

Screenshots or screen recordings

Before	After

How to set up and validate locally

1. Setup DAP for remote flows https://gitlab.com/gitlab-org/gitlab-development-kit/-/blob/main/doc/howto/duo_agent_platform.md?ref_type=heads#environment-setup-2-remote-flows
2. Via rails console bin/rails c enable Feature.enable :ai_dap_executor_connects_over_ws
3. Run DAP's flow session (eg: issue to MR, or fix pipeline)

MR acceptance checklist

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