AT2 CI Build Version Upgrade -- GCC 10->12

[sebrowne]

The current required gcc10-openmpi4 GitHub Action check (added with PR #14709) will be set to non-required and the gcc12-openmpi4 check will be set to required on Wednesday, 12/03/2025. The gcc10-openmpi4 check will be removed soon thereafter.

There has been limited history with the GCC12 compiler as of now, but it is a priority to upgrade the compiler to allow for a new version of Kokkos that is targeting the Trilinos 17.0.X releases.

If you encounter any issues that you think are related to this transition, please open an issue and tag @trilinos/framework.

[sebrowne]

Several test failures have been triaged:

SEACASIoss_pamgen_exodus_io_info -- failed once, was on trilogpu03, suspected machine issue with MPI (@achauphan investigating)
PanzerCore_memUtils_MPI_1 -- caused by kernel change, disabled with #14762
Intrepid2_unit-test_MonolithicExecutable_Intrepid2_Tests_MPI_1 -- known timeout issue, seen mainly on trilo002, will check machine loading

Balancing these against the need to upgrade GCC to get to Kokkos 5.0, the check change will commence and now be set to required (along with removing the requirement for GCC10 to pass).