message: Update PETSc version requirements.
diff: @@ -635,7 +635,8 @@ The specific libraries and their options are:
  --with-shared-libraries=0
  URL: https://www.mcs.anl.gov/petsc
  Options: PETSC_OPT, PETSC_LIB.
  - Versions: PETSc >= 3.8.0.
  + Versions: PETSc >= 3.8.0 (PETSc build without CUDA)
  + PETSc >= 3.15.0 (PETSc built with CUDA)
  - SLEPc (optional), used when MFEM_USE_SLEPC = YES. SLEPc depends on PETSc and
  uses some of the PETSc options when compiled.
  