rebase: bump google.golang.org/grpc from 1.55.0 to 1.56.0

Bumps [google.golang.org/grpc](https://github.com/grpc/grpc-go) from 1.55.0 to 1.56.0.
- [Release notes](https://github.com/grpc/grpc-go/releases)
- [Commits](https://github.com/grpc/grpc-go/compare/v1.55.0...v1.56.0)

---
updated-dependencies:
- dependency-name: google.golang.org/grpc
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

vendor/google.golang.org/grpc/internal/serviceconfig/duration.go

@@ -0,0 +1,130 @@
+/*
+ *
+ * Copyright 2023 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package serviceconfig
+
+import (
+	"encoding/json"
+	"fmt"
+	"math"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// Duration defines JSON marshal and unmarshal methods to conform to the
+// protobuf JSON spec defined [here].
+//
+// [here]: https://protobuf.dev/reference/protobuf/google.protobuf/#duration
+type Duration time.Duration
+
+func (d Duration) String() string {
+	return fmt.Sprint(time.Duration(d))
+}
+
+// MarshalJSON converts from d to a JSON string output.
+func (d Duration) MarshalJSON() ([]byte, error) {
+	ns := time.Duration(d).Nanoseconds()
+	sec := ns / int64(time.Second)
+	ns = ns % int64(time.Second)
+
+	var sign string
+	if sec < 0 || ns < 0 {
+		sign, sec, ns = "-", -1*sec, -1*ns
+	}
+
+	// Generated output always contains 0, 3, 6, or 9 fractional digits,
+	// depending on required precision.
+	str := fmt.Sprintf("%s%d.%09d", sign, sec, ns)
+	str = strings.TrimSuffix(str, "000")
+	str = strings.TrimSuffix(str, "000")
+	str = strings.TrimSuffix(str, ".000")
+	return []byte(fmt.Sprintf("\"%ss\"", str)), nil
+}
+
+// UnmarshalJSON unmarshals b as a duration JSON string into d.
+func (d *Duration) UnmarshalJSON(b []byte) error {
+	var s string
+	if err := json.Unmarshal(b, &s); err != nil {
+		return err
+	}
+	if !strings.HasSuffix(s, "s") {
+		return fmt.Errorf("malformed duration %q: missing seconds unit", s)
+	}
+	neg := false
+	if s[0] == '-' {
+		neg = true
+		s = s[1:]
+	}
+	ss := strings.SplitN(s[:len(s)-1], ".", 3)
+	if len(ss) > 2 {
+		return fmt.Errorf("malformed duration %q: too many decimals", s)
+	}
+	// hasDigits is set if either the whole or fractional part of the number is
+	// present, since both are optional but one is required.
+	hasDigits := false
+	var sec, ns int64
+	if len(ss[0]) > 0 {
+		var err error
+		if sec, err = strconv.ParseInt(ss[0], 10, 64); err != nil {
+			return fmt.Errorf("malformed duration %q: %v", s, err)
+		}
+		// Maximum seconds value per the durationpb spec.
+		const maxProtoSeconds = 315_576_000_000
+		if sec > maxProtoSeconds {
+			return fmt.Errorf("out of range: %q", s)
+		}
+		hasDigits = true
+	}
+	if len(ss) == 2 && len(ss[1]) > 0 {
+		if len(ss[1]) > 9 {
+			return fmt.Errorf("malformed duration %q: too many digits after decimal", s)
+		}
+		var err error
+		if ns, err = strconv.ParseInt(ss[1], 10, 64); err != nil {
+			return fmt.Errorf("malformed duration %q: %v", s, err)
+		}
+		for i := 9; i > len(ss[1]); i-- {
+			ns *= 10
+		}
+		hasDigits = true
+	}
+	if !hasDigits {
+		return fmt.Errorf("malformed duration %q: contains no numbers", s)
+	}
+
+	if neg {
+		sec *= -1
+		ns *= -1
+	}
+
+	// Maximum/minimum seconds/nanoseconds representable by Go's time.Duration.
+	const maxSeconds = math.MaxInt64 / int64(time.Second)
+	const maxNanosAtMaxSeconds = math.MaxInt64 % int64(time.Second)
+	const minSeconds = math.MinInt64 / int64(time.Second)
+	const minNanosAtMinSeconds = math.MinInt64 % int64(time.Second)
+
+	if sec > maxSeconds || (sec == maxSeconds && ns >= maxNanosAtMaxSeconds) {
+		*d = Duration(math.MaxInt64)
+	} else if sec < minSeconds || (sec == minSeconds && ns <= minNanosAtMinSeconds) {
+		*d = Duration(math.MinInt64)
+	} else {
+		*d = Duration(sec*int64(time.Second) + ns)
+	}
+	return nil
+}