Add blosc dep

Author: dstansby

pyproject.toml

@@ -13,8 +13,12 @@ name = "numcodecs"
 description = """
 A Python package providing buffer compression and transformation codecs \
 for use in data storage and communication applications."""
-readme = "README.rst"
-dependencies = ["numpy>=1.24", "typing_extensions"]
+readme =  "README.rst"
+dependencies = [
+    "numpy>=1.24",
+    "typing_extensions",
+    "blosc==1.11.2",
+]
 requires-python = ">=3.11"
 dynamic = [
   "version",