rebase: Bump google.golang.org/grpc from 1.53.0 to 1.54.0

Bumps [google.golang.org/grpc](https://github.com/grpc/grpc-go) from 1.53.0 to 1.54.0.
- [Release notes](https://github.com/grpc/grpc-go/releases)
- [Commits](https://github.com/grpc/grpc-go/compare/v1.53.0...v1.54.0)

---
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/metadata/metadata.go

@@ -76,33 +76,11 @@ func Set(addr resolver.Address, md metadata.MD) resolver.Address {
 	return addr
 }
 
-// Validate returns an error if the input md contains invalid keys or values.
-//
-// If the header is not a pseudo-header, the following items are checked:
-// - header names must contain one or more characters from this set [0-9 a-z _ - .].
-// - if the header-name ends with a "-bin" suffix, no validation of the header value is performed.
-// - otherwise, the header value must contain one or more characters from the set [%x20-%x7E].
+// Validate validates every pair in md with ValidatePair.
 func Validate(md metadata.MD) error {
 	for k, vals := range md {
-		// pseudo-header will be ignored
-		if k[0] == ':' {
-			continue
-		}
-		// check key, for i that saving a conversion if not using for range
-		for i := 0; i < len(k); i++ {
-			r := k[i]
-			if !(r >= 'a' && r <= 'z') && !(r >= '0' && r <= '9') && r != '.' && r != '-' && r != '_' {
-				return fmt.Errorf("header key %q contains illegal characters not in [0-9a-z-_.]", k)
-			}
-		}
-		if strings.HasSuffix(k, "-bin") {
-			continue
-		}
-		// check value
-		for _, val := range vals {
-			if hasNotPrintable(val) {
-				return fmt.Errorf("header key %q contains value with non-printable ASCII characters", k)
-			}
+		if err := ValidatePair(k, vals...); err != nil {
+			return err
 		}
 	}
 	return nil
@@ -118,3 +96,37 @@ func hasNotPrintable(msg string) bool {
 	}
 	return false
 }
+
+// ValidatePair validate a key-value pair with the following rules (the pseudo-header will be skipped) :
+//
+// - key must contain one or more characters.
+// - the characters in the key must be contained in [0-9 a-z _ - .].
+// - if the key ends with a "-bin" suffix, no validation of the corresponding value is performed.
+// - the characters in the every value must be printable (in [%x20-%x7E]).
+func ValidatePair(key string, vals ...string) error {
+	// key should not be empty
+	if key == "" {
+		return fmt.Errorf("there is an empty key in the header")
+	}
+	// pseudo-header will be ignored
+	if key[0] == ':' {
+		return nil
+	}
+	// check key, for i that saving a conversion if not using for range
+	for i := 0; i < len(key); i++ {
+		r := key[i]
+		if !(r >= 'a' && r <= 'z') && !(r >= '0' && r <= '9') && r != '.' && r != '-' && r != '_' {
+			return fmt.Errorf("header key %q contains illegal characters not in [0-9a-z-_.]", key)
+		}
+	}
+	if strings.HasSuffix(key, "-bin") {
+		return nil
+	}
+	// check value
+	for _, val := range vals {
+		if hasNotPrintable(val) {
+			return fmt.Errorf("header key %q contains value with non-printable ASCII characters", key)
+		}
+	}
+	return nil
+}