No response to initialize request

Issue:
The debug adapter doesn't respond to the following request:

Content-Length: 377\r\n\r\n{"type": "request", "seq": 1, "command": "initialize", "arguments": {"adapterID": "nvim-dap", "clientID": "neovim", "clientName": "neovim", "columnsStartAt1": true, "linesStartAt1": true, "locale": "en_US.UTF-8", "pathFormat": "path", "supportsProgressReporting": true, "supportsRunInTerminalRequest": true, "supportsStartDebuggingRequest": true, "supportsVariableType": true}}

Reason:
String.IndexOf(TWO_CRLF) returns -1 instead of the expected value 19
(related to: https://github.com/dotnet/runtime/issues/43736)

Fix:
Using a verbatim string solves the issue

protected const string TWO_CRLF = @"\r\n\r\n";

built using dotnet version 9.0.108
ran using mono version Mono JIT compiler version 6.8.0.105
on:

Distributor ID: Ubuntu
Description:    Ubuntu 24.04.2 LTS
Release:        24.04
Codename:       noble

Locate the TWO_CRLF constant in the debug adapter and reproduce the initialize request described in the issue on Ubuntu with Mono. Verify that the delimiter is found and that the adapter responds to initialize; the issue's proposed verbatim-string change indicates the expected direction.