Update dap-dart-setup to lsp-dart-dap-setup in prelude-dart.el

[ywkim]

This commit updates the deprecated function in prelude-dart.el to the latest one.

This PR aims to keep the Dart development environment in Emacs up-to-date.

🔍 Additional information:

• This change was introduced in lsp-dart v1.19.0. (Reference: https://github.com/emacs-lsp/lsp-dart/blob/9ffbafb7dcea3ef3d9e29bafb51d5167f0585d2c/CHANGELOG.md?plain=1#L79)
• The dap-dart-setup function is now deprecated and replaced by lsp-dart-dap-setup.

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by checking the relevant checkboxes):

• The commits are consistent with our contribution guidelines
• You've updated the changelog (if adding/changing user-visible functionality)
• You've updated the user manual (if adding/changing user-visible functionality like modules, commands, configuration options, etc)

Thanks!

[bbatsov]

Thanks!