feat(redisotel): add WithCallerEnabled option (#3415)

* feat(redisotel): add WithCaller option

Allow the disabling the collection of the `code.function`, `code.filepath` and `code.lineno` tracing attributes.
When setting `WithCaller(false)` overall performance is increased as the "expensive" `runtime.Callers` and `runtime.(*Frames).Next` calls are no longer needed.

* chore(redisotel): improve docblock language

* chore(redisotel): rename `WithCaller` to `WithCallerEnabled`

---------

Co-authored-by: Nedyalko Dyakov <1547186+ndyakov@users.noreply.github.com>

extra/redisotel/tracing_test.go

@@ -66,6 +66,35 @@ func TestWithDBStatement(t *testing.T) {
 	}
 }
 
+func TestWithoutCaller(t *testing.T) {
+	provider := sdktrace.NewTracerProvider()
+	hook := newTracingHook(
+		"",
+		WithTracerProvider(provider),
+		WithCallerEnabled(false),
+	)
+	ctx, span := provider.Tracer("redis-test").Start(context.TODO(), "redis-test")
+	cmd := redis.NewCmd(ctx, "ping")
+	defer span.End()
+
+	processHook := hook.ProcessHook(func(ctx context.Context, cmd redis.Cmder) error {
+		attrs := trace.SpanFromContext(ctx).(sdktrace.ReadOnlySpan).Attributes()
+		for _, attr := range attrs {
+			switch attr.Key {
+			case semconv.CodeFunctionKey,
+				semconv.CodeFilepathKey,
+				semconv.CodeLineNumberKey:
+				t.Fatalf("Attribute with %s statement should not exist", attr.Key)
+			}
+		}
+		return nil
+	})
+	err := processHook(ctx, cmd)
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
 func TestTracingHook_DialHook(t *testing.T) {
 	imsb := tracetest.NewInMemoryExporter()
 	provider := sdktrace.NewTracerProvider(sdktrace.WithSyncer(imsb))