enhance: test on Windows and fix what it found (#1348)

Adds a weekly and on-demand workflow that runs the cross-compiled tests on Windows Server 2025 Core in a [dockur/windows](https://github.com/dockur/windows) QEMU VM, and fixes the Windows bugs it found in host and UNC paths, env handling, shell quoting, post-task scripts, health checks, checkout, action symlinks, step summaries, Git client certificates and docker mode from a Windows host.

Host-mode steps now emit UTF-8, `bash` falls back to Git's bash instead of the WSL launcher, the runner can run as a native Windows service, steps can keep background helpers with `RUNNER_TRACKING_ID`, and Windows arm64 binaries are released.

Fixes: https://gitea.com/gitea/runner/issues/1339
Fixes: https://gitea.com/gitea/runner/issues/637
Fixes: https://gitea.com/gitea/runner/issues/1172
Fixes: https://gitea.com/gitea/runner/issues/347
Reviewed-on: https://gitea.com/gitea/runner/pulls/1348
Reviewed-by: bircni <[email protected]>

internal/app/cmd/daemon_test.go

@@ -145,7 +145,7 @@ func TestDaemonRetriesDeclareOutagesAndRemovesOnlyConsumedEphemeralRegistration(
 		{"ephemeral stopped during declare outage", true, true, connect.NewError(connect.CodeUnavailable, "bad gateway"), nil, false},
 	} {
 		t.Run(tc.name, func(t *testing.T) {
-			ctx, cancel := context.WithTimeout(t.Context(), 5*time.Second)
+			ctx, cancel := context.WithCancel(t.Context())
 			defer cancel()
 			service := &daemonTestService{declareErr: tc.declareErr, fetchErr: tc.fetchErr, beforeTask: tc.beforeTask, cancel: cancel}
 			rpcServer := connect.NewServer()