Refactor Buff Ending Announcer to Aura Expiry

- Deleted LibGroupInSpecT-1.1.toc, LibStub.lua, and lib.xml files as they are no longer needed.
- Updated localization files (deDE.lua, enUS.lua) to reflect the change from "Buff Ending" to "Aura Expiry".
- Renamed BuffEndingAnnouncer module to AuraExpiry and updated references throughout the codebase.
- Adjusted options and configuration to align with the new module name.
- Updated readme to describe the new Aura Expiry feature instead of Buff Ending Announcer.

HailMaryGuildToolsOptions.lua

@@ -1974,8 +1974,8 @@ function HMGT_Config:Initialize()
         end
 
         local buffEndingGroup = BuildNamedModuleGroup(
-            "announcer.buffEndingAnnouncer",
-            L["OPT_MODULE_BUFF_ENDING"] or "Buff Ending",
+            "announcer.auraExpiry",
+            L["OPT_MODULE_AURA_EXPIRY"] or L["OPT_MODULE_BUFF_ENDING"] or "Aura Expiry",
             20
         )
         if buffEndingGroup then