Modifications to deplete_with_transfer_rates regression test suite

[eepeterson]

Description

This PR makes the deplete_with_transfer_rates test suite more robust, by setting CoupledOperator.round_number = True. This is done in the deplete_with_transport regression tests to prevent simulations from diverging due to very tiny differences in atom number density. In addition, I tightened the tolerance on the assert_atoms_equal to be the same level of agreement (1e-6) as in the deplete_with_transport tests. Previously the reaction rate assertion had a tighter tolerance than the atom number when it should probably be the inverse. I also changed the test particle and batch numbers to match the other tests as well at the same time. This change also allows PRs #2764 and #2703 to pass without changing the test suite (at least locally).

Checklist

• I have performed a self-review of my own code
  - [ ] I have run clang-format (version 15) on any C++ source files (if applicable)
• I have followed the style guidelines for Python source files (if applicable)
  - [ ] I have made corresponding changes to the documentation (if applicable)
  - [ ] I have added tests that prove my fix is effective or that my feature works (if applicable)

[paulromano]

@eepeterson Thanks for all the (painful) work to figure this one out!