Update submodule deps for cmake 4

[HO-COOH]

Summarize your change.
Now that the latest cmake version goes to 4.x, and cmake <3.5 compatibility has been removed, which the pybind11 submodules uses. It's best to update all those submodules to latest.

Add a list of changes, and note any that might need special attention during review.

Reference associated tests.
CI are all passed.

[linux-foundation-easycla]

• ✅login: HO-COOH / (d7ad054)

The committers listed above are authorized under a signed CLA.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 84.86%. Comparing base (c0e97b0) to head (d7ad054).
⚠️ Report is 62 commits behind head on main.

❌ Your changes status has failed because you have indirect coverage changes. Learn more about Unexpected Coverage Changes and reasons for indirect coverage changes.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1918      +/-   ##
==========================================
+ Coverage   84.11%   84.86%   +0.74%     
==========================================
  Files         198      181      -17     
  Lines       22241    13054    -9187     
  Branches     4687     1206    -3481     
==========================================
- Hits        18709    11078    -7631     
+ Misses       2610     1790     -820     
+ Partials      922      186     -736     

Flag	Coverage Δ
py-unittests	84.86% <ø> (+0.74%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.
see 137 files with indirect coverage changes

---

Continue to review full report in Codecov by Sentry.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update f662359...d7ad054. Read the comment docs.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[darbyjohnston]

Hi, and sorry for the delay; we've updated the submodule dependencies to more recent versions: Imath v3.2.1, pybind11 v2.13.6, and the latest rapidjson. I believe these will work with CMake 4, but if not feel free to reopen this PR or create a new issue.