fragile cache name property pattern for _xpehh_gwss_cache_name and _ihs_gwss_cache_name

[kunal-10-cloud]

Problem

_xpehh_gwss_cache_name and _ihs_gwss_cache_name in anopheles.py (lines 183-191) exhibit the same fragile pattern that caused the crash bug reported in #1151.

These properties are declared as @property @abstractmethod in the base class but overridden by class attributes in species classes. Under MRO edge cases or version skew, this pattern can crash with NotImplementedError instead of returning the expected cache name string.

Root Cause

• Abstract properties rely on method resolution order (MRO) to locate class attribute overrides
• No fallback mechanism exists if MRO resolution fails
• Pattern is identical to the _roh_hmm_cache_name issue fixed in fix: resolve roh_hmm cache name safely (GH-1151) #1193

Impact

• Two latent crash bugs that could be triggered by version skew or edge cases
• Inconsistent with the corrected pattern already applied to _roh_hmm_cache_name

Solution

Apply the safe resolver pattern from #1193:

• Replace abstract properties with concrete _get_xpehh_gwss_cache_name() and _get_ihs_gwss_cache_name() methods
• Methods safely retrieve class attributes with fallback defaults
• Update call sites to use resolver methods instead of property access
• Remove fragile class attribute overrides from species classes

[kunal-10-cloud]

Hi @jonbrenas, I've opened a PR (#1199) for this issue, resolved all Copilot suggestions, and tested everything locally. Looking forward to your remarks and any suggestions to improve the implementation