Modify dependency strategy for sanitizer workflows in GitHub CI Actions

[oskooi]

The sanitizer workflows (UBSAN and ASAN) for the GitHub CI Actions are currently failing with the error: checking for hdf5... Package hdf5 was not found in the pkg-config search path.

The root cause of this error is the dpkg -i restore strategy on cache hit. Here's the problem:

1. On cache miss (first run): apt-get install properly installs libhdf5-dev and all its dependencies. Only the .deb files present in /var/cache/apt/archives/ are copied to ~/apt-cache/ — but packages already installed on the runner image aren't re-downloaded, so their .deb files are never cached.
2. On cache hit (subsequent runs): The runner image may have changed (Ubuntu updates the image periodically), but the cache key only hashes the workflow file, not the runner image. dpkg -i ~/apt-cache/*.deb tries to install the cached subset of packages, and 2>/dev/null || true silently suppresses dependency errors. The "Install Dependencies" step is skipped entirely, so any missing packages — like HDF5 dependencies that were pre-installed on the original image but removed in a newer image — are never installed.
3. The result: libhdf5-dev (or a dependency it needs to register its .pc file) is missing, so pkg-config --cflags hdf5 fails during ./configure.

The fix: Always run apt-get install for proper dependency resolution, but pre-populate apt's local archive from cache so it doesn't re-download packages that are already cached.