Doc updates for macOS 14.5 Sonoma

[eap]

This change updates the documentation to have additional information on installing spack-stack in a macOS 14.5 Sonoma environment. Some additional helpful info has been added on selecting a working clang compiler and several other smaller updates were added.

Issues

Fixes: #1123

[barlage]

If anyone's interested in my personal experience installing on macOS 14.5 Sonoma recently, here are my notes from running the commands in section 6.1.4-4. I did not brew install libiconv or need to externally find it. Also, perl seems to have been found from the first find. Not a spack power user, just some information if it's useful.

spack external find --scope system --exclude bison --exclude openssl --exclude python --exclude gettext

==> The following specs have been detected on this system and added to /Users/michael.barlage/spack-stack/envs/ufs.macos/site/packages.yaml
[email protected]   [email protected]  [email protected]  [email protected]  [email protected]       [email protected]
[email protected]  [email protected]  [email protected]  [email protected]     [email protected]  [email protected]

spack external find --scope system libiconv

==> No new external packages detected

spack external find --scope system perl

==> No new external packages detected

spack external find --scope system wget

==> The following specs have been detected on this system and added to /Users/michael.barlage/spack-stack/envs/ufs.macos/site/packages.yaml
[email protected]

PATH="$HOMEBREW_ROOT/opt/curl/bin:$PATH" spack external find --scope system curl

==> The following specs have been detected on this system and added to /Users/michael.barlage/spack-stack/envs/ufs.macos/site/packages.yaml
[email protected]

PATH="$HOMEBREW_ROOT/opt/qt@5/bin:$PATH" spack external find --scope system qt

==> The following specs have been detected on this system and added to /Users/michael.barlage/spack-stack/envs/ufs.macos/site/packages.yaml
[email protected]

[srherbener]

Thanks for addressing my comments!

[eap]

I've added some additional ignore directives to the CI workflows in preparation for a fix that should resolve the issue of missing required tests when changes are made to ignored directories (like docs or site configs). As an added benefit, this change triggered the required tests allowing the "notest" workflow variants to be submitted in a dedicated PR allowing further review and discussion on the change.