[benchmarks] Package name deprecation

All our workflows seem to already use "fuchsia-pkg:".

TEST=On CQ (peridot-x64-perf-dawson_canyon), + launched some benchmarks
manually using instructions from bin/ledger/benchmark/README.md.

LE-670 #done

Change-Id: I3e2d5467cba4d75aeef87ffa0e8f9b26e36def37
diff --git a/bin/ledger/tests/benchmark/BUILD.gn b/bin/ledger/tests/benchmark/BUILD.gn
index e2937ae..8cf9355 100644
--- a/bin/ledger/tests/benchmark/BUILD.gn
+++ b/bin/ledger/tests/benchmark/BUILD.gn
@@ -8,8 +8,6 @@
 visibility = [ "//peridot/bin/ledger/*" ]
 
 package("ledger_benchmarks") {
-  deprecated_bare_package_url = "//build"
-
   testonly = true
 
   deps = [