Add Slog adapter for async logging

Introduce a new `slogAdapter` to integrate `slog` with the `asynq` logging interface. This adapter implements Debug, Info, Warn, Error, and Fatal methods, providing seamless logging at various levels.

slog_adapter.go

@@ -0,0 +1,43 @@
+package asyncer
+
+import (
+	"log/slog"
+	"os"
+
+	"github.com/hibiken/asynq"
+)
+
+type slogAdapter struct {
+	log slog.Logger
+}
+
+func NewSlogAdapter(log slog.Logger) asynq.Logger {
+	return &slogAdapter{log: log}
+}
+
+// Debug logs a message at Debug level.
+func (s *slogAdapter) Debug(args ...interface{}) {
+	s.log.Debug("", args...)
+}
+
+// Info logs a message at Info level.
+func (s *slogAdapter) Info(args ...interface{}) {
+	s.log.Info("", args...)
+}
+
+// Warn logs a message at Warning level.
+func (s *slogAdapter) Warn(args ...interface{}) {
+	s.log.Warn("", args...)
+}
+
+// Error logs a message at Error level.
+func (s *slogAdapter) Error(args ...interface{}) {
+	s.log.Error("", args...)
+}
+
+// Fatal logs a message at Fatal level
+// and process will exit with status set to 1.
+func (s *slogAdapter) Fatal(args ...interface{}) {
+	s.log.Error("", args...)
+	os.Exit(1)
+}