Add BEAMMP_MAX_CONCURRENT_CONNECTIONS env var - #496

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@v2, actions/github-script@v6, actions/upload-artifact@v4. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

'=': conversion from 'int' to 'char', possible loss of data [D:\a\BeamMP-Server\BeamMP-Server\bin\BeamMP-Server.vcxproj]

'initializing': conversion from 'size_t' to 'uLongf', possible loss of data [D:\a\BeamMP-Server\BeamMP-Server\bin\BeamMP-Server.vcxproj]

'argument': conversion from 'size_t' to 'uLong', possible loss of data [D:\a\BeamMP-Server\BeamMP-Server\bin\BeamMP-Server.vcxproj]

'runtime_error': this base class is inaccessible [D:\a\BeamMP-Server\BeamMP-Server\bin\BeamMP-Server.vcxproj]

throwing 'InvalidDataError' the following types will not be considered at the catch site [D:\a\BeamMP-Server\BeamMP-Server\bin\BeamMP-Server.vcxproj]

'=': conversion from 'size_t' to 'uLongf', possible loss of data [D:\a\BeamMP-Server\BeamMP-Server\bin\BeamMP-Server.vcxproj]

'initializing': conversion from 'size_t' to 'uLongf', possible loss of data [D:\a\BeamMP-Server\BeamMP-Server\bin\BeamMP-Server.vcxproj]

'vsprintf': This function or variable may be unsafe. Consider using vsprintf_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details. [D:\a\BeamMP-Server\BeamMP-Server\bin\BeamMP-Server.vcxproj]

'vsprintf': This function or variable may be unsafe. Consider using vsprintf_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details. [D:\a\BeamMP-Server\BeamMP-Server\bin\BeamMP-Server.vcxproj]

'vsprintf': This function or variable may be unsafe. Consider using vsprintf_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details. [D:\a\BeamMP-Server\BeamMP-Server\bin\BeamMP-Server.vcxproj]

The following variables are not used in CMakeLists.txt:

boost-system's buildsystem uses very long paths and may fail on your

[LogCollection][Warn]File not found:'-- Loading CMake variables from D:/a/BeamMP-Server/BeamMP-Server/vcpkg/buildtrees/openssl/cmake-get-vars_C_CXX-x64-windows-static.cmake.log'.