allow use of deprecated ProtoReflectionService

[pjfanning]

• see comments in Update grpc-netty, grpc-protobuf, grpc-stub to 1.71.0 #1830
• I initially tried to use ProtoReflectionServiceV1 instead of deprecated ProtoReflectionService but one test failed

GrpcServiceScalaServerSpec:
[info] scala companion object
[info] - provides descriptor object
[info] scala server
[info]   reflection service
[info]   - listServices *** FAILED ***
[info]     java.util.concurrent.TimeoutException: Futures timed out after [3 seconds]
[info]     at scala.concurrent.impl.Promise$DefaultPromise.ready(Promise.scala:269)
[info]     at scala.concurrent.impl.Promise$DefaultPromise.result(Promise.scala:273)
[info]     at scala.concurrent.Await$.$anonfun$result$1(package.scala:223)
[info]     at scala.concurrent.BlockContext$DefaultBlockContext$.blockOn(BlockContext.scala:57)
[info]     at scala.concurrent.Await$.result(package.scala:146)
[info]     at GrpcServiceScalaServerSpec.$anonfun$new$6(GrpcServiceScalaServerSpec.scala:56)
[info]     at GrpcServiceSpecBase.$anonfun$withServer$1(GrpcServiceSpecBase.scala:57)
[info]     at GrpcServiceSpecBase.withManagedServer(GrpcServiceSpecBase.scala:63)
[info]     at GrpcServiceSpecBase.withServer(GrpcServiceSpecBase.scala:52)
[info]     at GrpcServiceSpecBase.withScalaServer(GrpcServiceSpecBase.scala:25)
[info]     ...