ci: lock bleeding edge to pybind11 latest version (#2069)

Identical to AcademySoftwareFoundation/OpenImageIO/pulls/5024

There's something in pybind11 master at the moment that is crashing in
its destructors. It's been causing our "bleeding edge" test to fail for
over a week now. I'm tired of our test failing, so I'm locking down to
the last known working version. Will check back periodically and return
to testing against pybind11 master after they have fixed it.

Signed-off-by: Larry Gritz <lg@larrygritz.com>

Author: lgritz

.github/workflows/ci.yml

@@ -465,7 +465,8 @@ jobs:
             opencolorio_ver: main
             openexr_ver: main
             openimageio_ver: main
-            pybind11_ver: master
+            pybind11_ver: v3.0.1
+            # pybind11_ver: master
             python_ver: "3.12"
             llvm_action_ver: "18.1.7"
             simd: avx2,f16c