[chore]: staticcheck linter fails on grpc_go/reflection/v1alpha being deprecated

[yurishkuro]

internal/grpctest/reflection.go:48:16: SA1019: grpc_reflection_v1alpha.ServerReflectionRequest is deprecated: The entire proto file grpc/reflection/v1alpha/reflection.proto is marked as deprecated. (staticcheck)
	err = r.Send(&grpc_reflection_v1alpha.ServerReflectionRequest{
	              ^

Upstream issue: grpc/grpc-go#5684 (comment)

[yurishkuro]

Per grpc/grpc-go#5684 (comment), the upstream issue is unlikely to be resolved anytime soon, so closing this to reduce noise.