Motivation

• Remove the failing legacy Windows workflow so the repository runs only the stable Ubuntu SFML CMake build.
• Prefer the distro-provided libsfml-dev install on ubuntu-latest to avoid brittle vcpkg/Windows-specific configuration and keep CI simple.

Description

• Deleted the legacy Windows workflow file .github/workflows/cmake-single-platform.yml which contained name: CMake on Windows, runs-on: windows-latest, and vcpkg steps.
• Renamed .github/workflows/cmake-windows.yml to .github/workflows/cmake.yml and retained the Ubuntu job body.
• Ensured the final workflow file has name: CMake Build, uses runs-on: ubuntu-latest, and installs dependencies with:
  sudo apt-get update and sudo apt-get install -y cmake g++ libsfml-dev.
• Verified there are no remaining references to windows-latest, vcpkg, Visual Studio, or windows-msvc in the workflows.

Testing

• Ran rg -n "CMake on Windows|windows-latest|vcpkg|Visual Studio|windows-msvc" .github/workflows || true to search for disallowed terms and it returned no matches in active workflows. (succeeded)
• Listed workflow files with rg --files .github/workflows to confirm only .github/workflows/cmake.yml remains. (succeeded)
• Checked repository status with git status --short to confirm the deletion and rename changes. (succeeded)
• Committed the changes with git add -A && git commit -m "ci: remove old Windows workflow and keep single Ubuntu build" and inspected the last commit with git show --name-status --oneline -1 to verify the delete and rename. (succeeded)

Codex Task