fix: format ErrorKind to avoid compilation error

[EricCrosson]

On one of my machines (just one 🤔) compiling helix on 6801b28
yields the following error

error[E0277]: `ErrorKind` doesn't implement `std::fmt::Display`
   --> helix-view/src/handlers/dap.rs:305:81
    |
305 | ...                   e => panic!("Error to start debug console: {}", e),
    |                                                                       ^ `ErrorKind` cannot be formatted with the default formatter
    |
    = help: the trait `std::fmt::Display` is not implemented for `ErrorKind`
    = note: in format strings you may be able to use `{:?}` (or {:#?} for pretty-print) instead
    = note: this error originates in the macro `$crate::const_format_args` (in Nightly builds, run with -Z macro-backtrace for more info)

For more information about this error, try `rustc --explain E0277`.
error: could not compile `helix-view` due to previous error

This commit takes the compiler's advice and uses the pretty-print
formatter.

[archseer]

Fixed in #2529