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/internal/rawhelpers.go

@@ -20,11 +20,13 @@ func RawToBool(r uint64) bool {
 }
 
 func Int64ToRaw(i int64) uint64 {
-	return uint64(i)
+	// Assumes original was a valid int64 (overflow not checked).
+	return uint64(i) // nolint: gosec
 }
 
 func RawToInt64(r uint64) int64 {
-	return int64(r)
+	// Assumes original was a valid int64 (overflow not checked).
+	return int64(r) // nolint: gosec
 }
 
 func Float64ToRaw(f float64) uint64 {
@@ -36,9 +38,11 @@ func RawToFloat64(r uint64) float64 {
 }
 
 func RawPtrToFloat64Ptr(r *uint64) *float64 {
-	return (*float64)(unsafe.Pointer(r))
+	// Assumes original was a valid *float64 (overflow not checked).
+	return (*float64)(unsafe.Pointer(r)) // nolint: gosec
 }
 
 func RawPtrToInt64Ptr(r *uint64) *int64 {
-	return (*int64)(unsafe.Pointer(r))
+	// Assumes original was a valid *int64 (overflow not checked).
+	return (*int64)(unsafe.Pointer(r)) // nolint: gosec
 }