Vectorization inconsistency between packed min/max

**Describe the bug**
I cannot understand why min and max have different vectorization macros (one has `vector_disabled`, while the other has `vector_simd`). It appears to me as a potential bug.

**To Reproduce**
Take a look at the two pairs of max/min implementation (masked and unmasked) around [this](https://github.com/E3SM-Project/EKAT/blob/4e301ff2edc742db7d232dcbcbba28e8c102c626/src/ekat/ekat_pack.hpp#L304) line.

**Expected behavior**
Either both `vector_simd` or both `vector_disabled`.

@jgfouca might know more about this, and either confirm or deny that this is a bug.

Open src/ekat/ekat_pack.hpp around line 304 and compare the masked and unmasked min/max implementation pairs. Trace how their vectorization macros are defined and used to determine whether the difference is intentional or a bug. Done means the two implementations have a confirmed, consistent vectorization choice.

Written by the indexing model from the issue text.