Remove port manager and range parser

That code is no longer needed since both cdc_stream and cdc_rsync use
ephemeral ports assigned by the OS now.

cdc_rsync/BUILD

@@ -113,7 +113,6 @@ cc_library(
     deps = [
         ":cdc_rsync_client",
         "//common:build_version",
-        "//common:port_range_parser",
         "@com_github_zstd//:zstd",
         "@com_google_absl//absl/status",
     ],