rebase: bump google.golang.org/grpc from 1.68.1 to 1.69.0

Bumps [google.golang.org/grpc](https://github.com/grpc/grpc-go) from 1.68.1 to 1.69.0.
- [Release notes](https://github.com/grpc/grpc-go/releases)
- [Commits](https://github.com/grpc/grpc-go/compare/v1.68.1...v1.69.0)

---
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/go.opentelemetry.io/otel/trace/tracer.go

@@ -0,0 +1,37 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package trace // import "go.opentelemetry.io/otel/trace"
+
+import (
+	"context"
+
+	"go.opentelemetry.io/otel/trace/embedded"
+)
+
+// Tracer is the creator of Spans.
+//
+// Warning: Methods may be added to this interface in minor releases. See
+// package documentation on API implementation for information on how to set
+// default behavior for unimplemented methods.
+type Tracer interface {
+	// Users of the interface can ignore this. This embedded type is only used
+	// by implementations of this interface. See the "API Implementations"
+	// section of the package documentation for more information.
+	embedded.Tracer
+
+	// Start creates a span and a context.Context containing the newly-created span.
+	//
+	// If the context.Context provided in `ctx` contains a Span then the newly-created
+	// Span will be a child of that span, otherwise it will be a root span. This behavior
+	// can be overridden by providing `WithNewRoot()` as a SpanOption, causing the
+	// newly-created Span to be a root span even if `ctx` contains a Span.
+	//
+	// When creating a Span it is recommended to provide all known span attributes using
+	// the `WithAttributes()` SpanOption as samplers will only have access to the
+	// attributes provided when a Span is created.
+	//
+	// Any Span that is created MUST also be ended. This is the responsibility of the user.
+	// Implementations of this API may leak memory or other resources if Spans are not ended.
+	Start(ctx context.Context, spanName string, opts ...SpanStartOption) (context.Context, Span)
+}