ci: add windows build

[gballet]

No description provided.

[Copilot]

Pull Request Overview

This PR adds Windows to the CI build matrix to ensure the project is tested across all major operating systems (Linux, macOS, and Windows).

Key Changes:

• Extended the CI build matrix to include windows-latest alongside existing Ubuntu and macOS builds

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[gballet]

This is not going to happen right off the bat:

C:\Users\runneradmin\AppData\Local\zig\p\rocksdb-9.7.4-z_CUTmO5AAD0CQ2ZvShSDZHjC2x9MKrTnpvbNAIU7ah0\build.zig:473:9: 0x7ff75aec390b in buildRocksDB (build.exe.obj)
        @panic("TODO: support windows!");