doc: update doi for PETSc users manual

Merge remote-tracking branch 'origin/release'

PetscOptions - doc - Move documentation to PetscOptions macros

Merge remote-tracking branch 'origin/release'

Remove incorrect constexpr

Fix PetscOptionsGetViewer() so it works in a thread-safe way

When PetscOptionsGetViewer() returns, for example, PETSC_VIEWER_STDOUT_SELF the same object is shared
by all threads that call PetscOptio

Fix PetscOptionsGetViewer() so it works in a thread-safe way

When PetscOptionsGetViewer() returns, for example, PETSC_VIEWER_STDOUT_SELF the same object is shared
by all threads that call PetscOptionsGetViewer(). In the previous code PetscObjectReference() and
dereference (via PetscViewerDestroy() where called on the viewer by multiple threads after the viewer
was accessed thus corrupting the object.

This branch introduces a PetscOptionsRestoreViewer() that allows not doing the referencing and dereferencing
on persistant viewers, thus removing the specific race condition above.

Other possible solutions include

Use a lock on each PetscObjectReference/Dereference() just in case they are shared. Could be time consuming so one
could mark each object as either threadshared or independent and only do the locks on threadshared objects. This lowers
the cost but would require more extensive changes to PETSc infrastructure. And I do not know if this shared/not shared model
is what we need in the long run, though it might be.

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Ensure no leading white spaces in front of .seealso:

Fix for missing blis.h include when using BLIS from AOCL

Merge branch 'barry/2023-10-19/fix-pcview-redundant/release' into 'main'

Fix bugs in handling PetscViewerGetSubViewer() and tabing in ASCII viewers

See merge request petsc/petsc!6948

Merge remote-tracking branch 'origin/release'

Docs: misspelling of threads

Fix bugs in handling PetscViewerGetSubViewer() and tabing in ASCII viewers

Reported-by: Pierre Jolivet

C functions and doctext comments should not be in Fortran directories include ft-custom

Merge branch 'barry/2023-07-30/doc-better-blas-thread-usage' into 'main'

Start of PETSc benchmarking object

See merge request petsc/petsc!6772

Merge remote-tracking branch 'origin/release'

Merge branch 'barry/2023-11-01/docs-kspcomputeeigenvalues/release' into 'release'

Fix manual pages in ksp/interface files

See merge request petsc/petsc!6988

Add support for managing the number of threads BLAS uses

Fix capitalization of fortran

Commit-type: housekeeping

Sys: error out when provided mpi thread level does not meet needs

Merge branch 'release'

Remove unneeded on in Collective statements and fix Collective over

Commit-type: documentation

Rename rules.doc and rules.utils because GitLab treats the former as a MS Word document.

Thanks-to: Jed Brown

Merge branch 'barry/2023-10-18/rm-dirs-from-makefiles' into 'main'

Remove use of and the DIRS variables from the makefiles

See merge request petsc/petsc!6945

Remove DIRS variable and unneeded tabs from all makefiles since no longer needed

Commit-type: housekeeping

Merge remote-tracking branch 'origin/release'