Fix the layers dependencies which required a lsp backend

[sunlin7]

Fix the layers dependency which required a lsp backend.
These layers configuration indicate user want lsp feature, so the layer should depends on the lsp.

[bcc32]

The dap layer depends on lsp already. If I understand correctly, users who do use dap features would see breaking behavior after this change.

[sunlin7]

@bcc32 Hidden logic here for the user who want lsp backend but the layer depends on dap, just because of dap layer had requested the lsp layer.

This patch corrects the dependencies relations. (the dap depends on lsp from its implementation, but the lsp should not depends on dap for the dap will affect the user experience a lot, the dap is heavy and under developing).

The dap layer should be explicitly configured in dot spacemacs file if user really use it.

[sunlin7]

It's a bug, not a feature, for the layers who actually should depend on the lsp but currently depends on the dap works for user.

[bcc32]

It's a bug, not a feature, for the layers who actually should depend on the lsp but currently depends on the dap works for user.

No, this is a deliberate feature. I suppose in theory it could specify both dap and lsp as dependencies, but it is intentional that enabling go layer with go-backend set to lsp will implicitly activate `dap layer. See this commit for an example of the historical context.

dap will affect the user experience a lot, the dap is heavy and under developing).

If you want a way to opt out of dap while still using lsp for go-backend, maybe we should just add a new config variable instead of piggy-backing on go-backend.

My objection is only that we should try to stay backwards compatible with existing user's configs, and the proposed change is currently incompatible.

[sunlin7]

If you want a way to opt out of dap while still using lsp for go-backend, maybe we should just add a new config variable instead of piggy-backing on go-backend.

That's what I want, I used the lsp daily, but never use the dap, and the dap make Spacemacs slow on opening a simple *.py or *.c file.

[bcc32]

Makes sense, let's add a new variable then.