Remove build hacks that are no longer needed

[henryleberre]

• Removed CCE 16 workgroup hacks.
• Removed Silo patch for HDF5 on Frontier.
• Removed AppleClang workarounds on macOS, including building MPI from scratch.
• Only build HDF5, FFTW, and SILO packages if they are not installed/compatible.
• Removed Docker (nobody uses it, and maintaining it is cumbersome).
• Switched to using the proper Silo patch for an error on GNU 13 and above. See my comment here: Silo does not compile with gcc 14 LLNL/Silo#375 (comment).
• Removed installation instructions for Arch Linux. They installed their operating system, I'm sure they can install gcc.
• Removed our FindHDF5 file. We can use the built-in.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 53.99%. Comparing base (cf3ac9f) to head (daef835).
Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #599      +/-   ##
==========================================
+ Coverage   53.28%   53.99%   +0.70%     
==========================================
  Files          58       58              
  Lines       14150    13719     -431     
  Branches     1729     1635      -94     
==========================================
- Hits         7540     7407     -133     
+ Misses       6097     5867     -230     
+ Partials      513      445      -68     

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[sbryngelson]

[TODO] Check FOM is roughly the same w/o workaround for workgroup size on CCE18.

[sbryngelson]

• Removed installation instructions for Arch Linux. They installed their operating system, I'm sure they can install gcc.

🤣 🤣 🤣
You might still leave them a list of packages they need. MFC's dependencies are not obvious other than from our installation instructions.

[henryleberre]

• Removed installation instructions for Arch Linux. They installed their operating system, I'm sure they can install gcc.

🤣 🤣 🤣 You might still leave them a list of packages they need. MFC's dependencies are not obvious other than from our installation instructions.

The assumption is that they can look at those needed on Debian as reference. The only one that isn't obvious is gcc-fortran but solving that is one error and a google search.