bump pybind11 to 2.10.0

- allow arbor to be build against py3.11
- modernise!

pybind11 @ aa304c9c

-Subproject commit f7b499615e14d70ab098a20deb0cdb3889998a1a
+Subproject commit aa304c9c7d725ffb9d10af08a3b34cb372307020

spack/package.py

@@ -79,6 +79,7 @@ class Arbor(CMakePackage, CudaPackage):
     with when("+python"):
         depends_on("py-pybind11@2.6:", type=("build"))
         depends_on("py-pybind11@2.8.1:", when="@0.5.3:", type=("build"))
+        depends_on("py-pybind11@2.10.0:", when="@0.7.1:", type=("build"))
 
     # sphinx based documentation
     depends_on("python@3.7:", when="+doc", type="build")