[CI] Weekly CI and introducing a new amdgpu matrix generator

[HereThereBeDragons]

This introduces a new weekly CI.

To make this comfortable, larger changes of the amdgpu matrix generator were necessary. The amdgpu matrix generator can now be used to create build, test and/or release target config in a single run for both Windows and Linux. For pull request it keeps the functionality of dynamically deciding based on the modified files if it needs to build the target or not.

In addition, the new_setup.yml is used to provide the container image. It can either use the default CI TheRock image or accepts a custom one.

[HereThereBeDragons]

@marbre @ScottTodd @geomin12 @jayhawk-commits

just for info:
This is now at a state where I will fan this out into smaller PRs to get it merge.

• new amdgpu_matrix layout and corresponding configure_amdgpu_matrix.py (replacing configure_ci.py); missing is the multi_arch generator(). will be done in 2nd step. this already integrated some version of geo's [ci] Adding ability to run kernel-specified test runners #2902
• ci_weekly using the new layout/allowing to set container image that has now a default at central location (new_)setup.yml

this would run in parallel until all workflows are transferred. only needs to be adjusted for the high level workflows.

Successful cmake4 run (rebase on main from last Friday or this Monday?): https://github.com/ROCm/TheRock/actions/runs/21402078653
new run: https://github.com/ROCm/TheRock/actions/runs/21407180474

new layout of the matrix for the workflows:

amdgpu_family_matrix:
{'linux': [{'amdgpu_family': 'gfx94X-dcgpu',
            'build': {'artifact_group': 'gfx94X-dcgpu',
                      'build_variant_cmake_preset': '',
                      'build_variant_label': 'release',
                      'build_variant_suffix': '',
                      'expect_failure': False},
            'test': {'expect_pytorch_failure': False,
                     'run_tests': True,
                     'runs_on': {'benchmark': 'linux-mi325-1gpu-ossci-rocm-frac',
                                 'test': 'linux-mi325-1gpu-ossci-rocm-frac'},
                     'sanity_check_only_for_family': False}}]}

build, test, release are only added when requested and if there is content (e.g. no test runners = no test config returned). same with windows and linux.