Changes

Add spack-based workflow to add all supported Geant4 versions to CI (#1149)

* Add note about pull requests
* Show ccache stats even on failure
* Add spack-based CI build
* Add spack build to push/pr
* Mark failing builds as experimental
* Fix missing compiler/version from matrix
* Use patched geant4 in upstream spack
* Use only celer buildcache
* Shorten padded length
* Don't push the buildcache...
* Load version information to fix examples

Fix Geant4 build from 10.5–10.7 and example build for 11.1 onward (#1152)

* Add additional components in CeleritasConfig
* Remove obsolete requirement in CeleritasConfig
* Fix downstream (example) build with Geant4 11.1+
* Fix build for Geant4 10.5–10.7
* Fix example execution for Geant4@11.1+
* Add geant4 compatibility ranges
* Remove experimental status from geant builds

Rename `Wentzel` model to `CoulombScattering` and add em/params subdirectory (#1154)

* Rename Wentzel model classes to CoulombScattering

* Move em params to subdirectory

* Move MscParamsHelper to params/detail and fix namespace

Add generic grid builder and refactor builder code that uses generic grids (#1157)

* Refactor particle insertion to use helper class
* Add size attribute to interp
* Initialize grid record
* Deduplicate value grids
* Revert "Deduplicate value grids": The in-place modification for elemental CDFs does not work!!
* IWYU and order backend data after main data
* Rename ValueGridType file
* Add generic grid builder
* Remove unused generic value grid builder
* Remove support for anything but linear/linear
* Use grid builder for cerenkov, neutron data
* Refactor livermore xs inserter
* Fix missing inline
* Fix single precision build
* Address review feedback

Update CI images and workflow actions (#1136)

* Use node v20 actions for native pipelines
* Fix duplicate ID
* Just upload as artifacts instead of github pages
* Refactor runners to use more spack, less docker
* Disable SWIG until it gets fixed

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