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]>

act/runner/expression.go

@@ -10,7 +10,6 @@ import (
 	"errors"
 	"fmt"
 	"maps"
-	"path"
 	"reflect"
 	"regexp"
 	"strings"
@@ -160,7 +159,7 @@ func getHashFilesFunction(ctx context.Context, rc *RunContext) func(v []reflect.
 				Name: name,
 				Mode: 0o644,
 				Body: hashfiles,
-			}).Then(rc.JobContainer.Exec([]string{"node", path.Join(rc.JobContainer.GetActPath(), name)}, env, "", ""))(timeoutCtx)
+			}).Then(rc.JobContainer.Exec([]string{"node", container.JoinPath(rc.JobContainer.GetActPath(), name)}, env, "", ""))(timeoutCtx)
 			quotedPatterns := expressionStringEscape(strings.Join(patterns, ", "))
 			switch {
 			case err == nil: