Reduce unnecessary work in dependency builds

[sbryngelson]

Summary

• HDF5: Remove invalid -DFORTRAN_LIBRARIES=ON (not a real HDF5 CMake variable; was a no-op). Explicitly disable C++ bindings, Fortran bindings, and parallel I/O that MFC doesn't use — fewer source files to compile.
• Silo: Add GIT_SHALLOW ON (was missing unlike other deps) and disable ZFP compression (-DSILO_ENABLE_ZFP=OFF). MFC never uses Silo compression, so this removes ~33 ZFP source files from the build.

Test plan

• Build post_process from clean state, verify deps build and link correctly
• Run post-process on a case that writes .silo output and confirm files are valid
• Verify h5dump still works in test suite (HDF5 tools are still enabled)

[github-actions]

Claude Code Review

Incremental review from: ea00665
Head SHA: 10c55e5

New findings since last Claude review:

• $job_cluster is undefined in run_case_optimization.sh (line 47): The new -c "$job_cluster" argument references a variable that is never set in this script and is not listed as an expected injected environment variable. The file's own header comment (line 4) documents only $job_device and $job_interface as variables expected from submit.sh — $job_cluster is absent. If unset at runtime, the command expands to -c "", passing an empty cluster name to ./mfc.sh run, which will either silently misbehave or error. The variable needs to either be exported by submit.sh (and documented in the header) or guarded in the script before use.