Fix test/unpack_strategy/zstd for Ubuntu 22.04

Library/Homebrew/test/unpack_strategy/zstd_spec.rb

@@ -6,5 +6,12 @@
 describe UnpackStrategy::Zstd do
   let(:path) { TEST_FIXTURE_DIR/"cask/container.tar.zst" }
 
-  include_examples "UnpackStrategy::detect"
+  it "is correctly detected" do
+    # UnpackStrategy.detect(path) for a .tar.XXX file returns either UnpackStrategy::Tar if
+    # the host's tar is able to extract that compressed file or UnpackStrategy::XXX otherwise,
+    # such as UnpackStrategy::Zstd. On macOS UnpackStrategy.detect("container.tar.zst")
+    # returns UnpackStrategy::Zstd, and on ubuntu-22.04 it returns UnpackStrategy::Tar,
+    # because the host's version of tar is recent enough and zstd is installed.
+    expect(UnpackStrategy.detect(path)).to(be_a(described_class).or(be_a(UnpackStrategy::Tar)))
+  end
 end