debugger: More tidy up for SSH (#28993)

Split `locator` out of DebugTaskDefinition to make it clearer when
location needs to happen.

Release Notes:

- N/A

---------

Co-authored-by: Anthony Eid <hello@anthonyeid.me>
Co-authored-by: Anthony <anthony@zed.dev>
Co-authored-by: Cole Miller <m@cole-miller.net>

crates/zed/Cargo.toml

@@ -42,7 +42,6 @@ command_palette.workspace = true
 command_palette_hooks.workspace = true
 component_preview.workspace = true
 copilot.workspace = true
-dap.workspace = true
 dap_adapters.workspace = true
 debugger_ui.workspace = true
 debugger_tools.workspace = true