Merge branch 'barry/2025-09-04/deprecate-mpiu-bool' into 'main'

Deprecate MPIU_BOOL which used to be for PETSc's enum Bool but now is just MPI_C_BOOL

See merge request petsc/petsc!8691

Deprecate MPIU_BOOL which used to be for PETSc' enum Bool but now is just MPI_C_BOOL so no longer needs its own name

Merge remote-tracking branch 'origin/release'

Merge branch 'jed/egrep-obsolescent' into 'release'

Replace egrep with grep -E

See merge request petsc/petsc!8320

Replace egrep with grep -E

On recent systems, egrep will print this on stderr:

egrep: warning: egrep is obsolescent; using grep -E

This has been fixed before (petsc/petsc!5674), but crept back in.

Merge branch 'jolivet/remove-cast' into 'main'

Use NULL or nullptr instead of casted 0

See merge request petsc/petsc!7857

Use NULL or nullptr instead of casted 0

Merge branch 'barry/2024-09-02/rebased-fix-conversion-warnings' into 'main'

Compiler finds (and forbid) casts from higher precision integers to lower

See merge request petsc/petsc!7806

Fix MPIU_* routines to always return MPI error codes and thus be usable with PetscCallMPI()

Introduce MPIU_Count to be used when MPI_Count is not available