Remove test that depends on Random being in the sysimg (#3656)

Author: vchuravy

test/api.jl

@@ -271,7 +271,6 @@ import .FakeTerminals.FakeTerminal
         @test_throws Pkg.Types.PkgError Pkg.precompile("DoesNotExist") # fail to find a nonexistant dep in an empty env
 
         Pkg.add("Random")
-        @test_throws Pkg.Types.PkgError Pkg.precompile("Random") # Random is a dep but in the sysimage
         @test_throws Pkg.Types.PkgError Pkg.precompile("DoesNotExist")
         Pkg.precompile() # should be a no-op
     end end