go-librespot gained first-party WASAPI output for Windows in v0.9.0
(cliamp was pinned to v0.7.1, which doesn't compile on Windows). Bump
the dependency and remove the Windows CGO stub so the real provider
builds on all platforms.
CI now installs a MinGW toolchain via MSYS2 and builds/tests with
CGO_ENABLED=1 on windows-2025, including a workaround for an MSYS2
libogg packaging issue where libogg-0.dll's export table is missing
ogg_stream_iovecin even though it's present in the static libogg.a.
Verified locally end-to-end on Windows: native CGO build, full test
suite, and real Spotify Premium playback.
Fixes#299
Not in scope for this PR: release.yml still builds Windows with
CGO_ENABLED=0, so Releases binaries won't include Spotify until that
pipeline is updated separately (needs a packaging decision: bundle the
MSYS2 DLLs or pursue a fully static build).
Luguin
49c2cc7983