Fix warning in CI jobs (#467)

!!

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          newlines are not allowed in `summary` and will break in the future
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  !!

Author: DimitriPapadopoulos

pyproject.toml

@@ -10,9 +10,8 @@ build-backend = "setuptools.build_meta"
 [project]
 name = "numcodecs"
 description = """
-A Python package providing buffer compression and transformation codecs for use
-in data storage and communication applications.
-"""
+A Python package providing buffer compression and transformation codecs \
+for use in data storage and communication applications."""
 readme =  "README.rst"
 dependencies = [
     "numpy>=1.7",
@@ -120,4 +119,4 @@ norecursedirs = [
  [[tool.cibuildwheel.overrides]]
  select = "*-macosx_arm64"
  environment = { DISABLE_NUMCODECS_SSE2=1 }
- 
+