tests: update test for dictionary ID in header
tests: update test for dictionary ID in header

On macOS, the dictionary ID is different. Weird, but OK. The
exact dictionary ID isn't important for this test. So allow it
to be dynamic.
indygreg/python-zstandard,indygreg/python-zstandard,indygreg/python-zstandard,indygreg/python-zstandard