Replace Logger interface with slog.Logger

[iwarapter]

The current log implementation uses a custom interface to expose a logger:

// Logger defines an interface for logging errors.
type Logger interface {
	Error(args ...interface{})
}

type noopLogger struct{}

func (noopLogger) Error(...interface{}) {}

With go 1.21 a structured log package was introduced - https://go.dev/blog/slog

Would you accept a PR that swaps out the existing logger for a *slog.Logger and updating all the relevant internal calls to be context based. I'm happy to work on this if it's likely to be accepted.

[q-uint]

Thanks for the suggestion! This makes sense, but since we're currently on Go 1.16, we'd need to bump our minimum version to at least 1.21 first. Let's keep this issue open until then.

When we do, the changes should be straightforward:

• Replace the Logger interface and noopLogger in logger.go with *slog.Logger
• Update the log field on the server struct and WithLogger option to accept *slog.Logger
• Default to a discarding logger (or slog.Default()) when no logger is provided