Merge branch 'release_29'

* release_29: (29 commits)
  Bump version to v2.9.2
  ci: update number of task for mpich build
  clang-format: Correct format to old style
  Merge pull request #3878 from anagainaru/test-null-blocks
  Merge pull request #3588 from vicentebolea/fix-mpi-dp
  bp5: make RecMap an static anon namespaced var
  Replace LookupWriterRec's linear search on RecList with an unordered_map. For 250k variables, time goes from 21sec to ~1sec in WSL. The order of entries in RecList was not necessary for the serializer to work correctly. (#3877)
  Fix data length calculation for hash (#3875)
  Merge pull request #3823 from eisenhauer/SstMemSel
  gha,ci: update checkout to v4
  Blosc2 USE ON: Fix Module Fallback
  cmake: correct prefer_shared_blosc behavior
  cmake: correct info.h installation path
  ci: disable MGARD static build
  operators: fix module library
  ci: add downloads readthedocs
  cmake: Add Blosc2 2.10.1 compatibility.
  Fix destdir install test (#3850)
  cmake: update minimum cmake to 3.12 (#3849)
  MPI: add timeout for conf test for MPI_DP (#3848)
  ...