Try to optimize caching speed by limiting to hicolor icons, for now

engine/findicons.py

@@ -39,10 +39,10 @@ SEARCH_DIRECTORIES = [pathlib.Path(pathlib.Path.home(), ".icons")]
 
 XDG_DATA_DIRS = getenv("XDG_DATA_DIRS")  #colon : separated, most likely empty
 if XDG_DATA_DIRS:
-    SEARCH_DIRECTORIES += [pathlib.Path(p, "icons") for p in XDG_DATA_DIRS.split(":")]
+    SEARCH_DIRECTORIES += [pathlib.Path(p, "icons/hicolor") for p in XDG_DATA_DIRS.split(":")]
 else:
     #If $XDG_DATA_DIRS is either not set or empty, a value equal to /usr/local/share/:/usr/share/ should be used.
-    SEARCH_DIRECTORIES += [pathlib.Path(p, "icons") for p in "/usr/local/share/:/usr/share/".split(":")]
+    SEARCH_DIRECTORIES += [pathlib.Path(p, "icons/hicolor") for p in "/usr/local/share/:/usr/share/".split(":")]
 
 SEARCH_DIRECTORIES.append(pathlib.Path("/usr/share/pixmaps"))