Remove spec

It does allocate too much memory, which breaks on CI, is definitely too large on 32-bit targets, and is far too slow overall, even on fast hardware.

spec/std/hash_spec.cr

@@ -1393,10 +1393,6 @@ describe "Hash" do
     hash.@indices_size_pow2.should eq(12)
   end
 
-  it "creates with max capacity", tags: %w[slow] do
-    Hash(Int32, Int32).new(initial_capacity: Int32::MAX)
-  end
-
   describe "#rehash" do
     it "rehashes" do
       a = [1]