Fixes formatting of reference and pointer variables

[kennyweiss]

Summary

• This maintenance PR updates our .clang-format
  • It ensures that we consistently place the * and & for pointers and references next to the type rather than the variable
  • It ensures that line ending are LF (instead of CRLF)
  • It updates the language to C++17
    • we should change it to C++20 when Update to C++20, spack 1.2.0 and package updates #1912 merges
  • It updates the link/commit at the top to clang@19, instead of clang@14
  • It removes obsolete/deprecated attributes from our .clang-format
    • I verified that the associated commit has no formatting changes

Since this merge will affect all outstanding existing branches, it probably makes sense to merge this close to the upcoming August release.

• I added a huge commit with all of the formatting changes related to the pointer/references/crlf, but will plan to redo that commit before merging.

[kennyweiss]

This file contains the only hand-edited changes.
Many of the changes were related to removing obsolete/deprecated features, and updating to the new ones.
Tested using clang-format --dump-config

The rest of the files in this PR are automatically generated via make style
(Note: Reviewing with "Hide whitespace" reveals that nearly every change in this PR is a whitespace change.)

[kennyweiss]

These two control the placement of T* ptr and T& ref

The DerivePointAligment: false a few lines up says not to use the style found in the file.

[jcs15c]

Looks good to me! It is indeed mostly whitespace changes.

[kennyweiss]

Now that we're past clang@11, do we want to set BraceWrapping/BeforeLambdaBody: true?

If so, we'd check changes like this:

I can see both sides: Lambda curly brace wrapping on a separate line would be more consistent w/ our other choices, but somehow, I've grown used to seeing lambda curly braces at the end of a line.

We can also defer this decision to a follow-up PR if we can't reach a quick consensus.