Update du

Note, I'm on a mac machine, so `du -sb` is unavailable. However,
`find tests/data -type f -exec stat -f %z {} + | awk '{s+=$1} END {print s}'`
*seems* to work?

Author: ACEnglish

tests/test_core.py

@@ -237,8 +237,8 @@ def test_examples(self, chunk_size, size, start, stop):
         # It works in CI on Linux, but it'll probably break at some point.
         # It's also necessary to update these numbers each time a new data
         # file gets added
-        ("tests/data", 4976329),
-        ("tests/data/vcf", 4964192),
+        ("tests/data", 4957158),
+        ("tests/data/vcf", 4953213),
         ("tests/data/vcf/sample.vcf.gz", 1089),
     ],
 )