Release v2.9.0

Alfio Lazzaro:
Switch MacOS CI to use MPICH
Update GCC to v15
Install ACC header only for the OpenCL backend
Remove G2G in ROCM (it is enabled), add MPI
Fix FORD documentation for notes
Conditional C/C++ Standard requirements
Add CUDA and HIP C++ Standard
Fix issue on Fedora due to missing FindBlas/Lapack
Add Flang compiler flags

Cristian Le:
Add Fedora packaging via packit

Eisuke Kawashima:
build: add flags for LLVMFlang
build: add flags for IntelLLVM (#928)

Gina Sitaraman:
Add linking with hiprtc library, needed for ROCm 7.x, unused in older ROCm versions
Add gfx950 (Mi350) GPU architecture support
Add Mi300 arch

Hans Pabst:
Fixed looking-up bogus environment variables (#915)
HIP:
- Removed unused hipHostAllocDefault
- Fixed compilation error
CMake cleanup:
- Removed customized/diverged modules (LAPACK/BLAS)
- Allow USE_SMM=auto (#889)
OpenCL:
- Allow CP2K to use DBCSR for DBM (and the other way around)
- Improved matching a device with a parameter set
- Improved script for auto-tuning of parameters
- Updated tuned parameters (Mi250, GH200, PVC, BMG)
- Fixed leaking event objects
LIBXSMM: improved supporting shared library

Mathieu Taillefumier:
CMake: proper handling of the different language standards

Ole Schütt:
Check block sizes are equal in dbcsr_copy_into_existing_sym