fix default determination to handle symlinked casa installs

This has been tested locally

shared/workspaces/workspaces/system/services/casa_matrix_service.py

@@ -58,25 +58,16 @@ def casa_version_from_path(path: str) -> str:
     # Defaults
     casa_version, pipeline_version = "unknown", "default"
 
-    def check_regex(regex: str, path_str: str) -> re.Match[str] | None:
-        """
-        check casa paths against version and pipeline regexes
-        :param regex:
-        :param path_str:
-        :return:
-        """
-        return re.search(regex, path_str)
-
-    cv_search = check_regex(CASA_VERSION_REGEX, path)
+    cv_search = re.search(CASA_VERSION_REGEX, path)
 
     if cv_search is None:
         # this is probably a default link, make sure we use the actual version path
         path2 = pathlib.Path(path)
         if path2.is_symlink():
             path = str(path2.readlink())
-            cv_search = check_regex(CASA_VERSION_REGEX, path)
+            cv_search = re.search(CASA_VERSION_REGEX, path)
 
-    pv_search = check_regex(PIPELINE_VERSION_REGEX, path)
+    pv_search = re.search(PIPELINE_VERSION_REGEX, path)
 
     if cv_search:
         # Replace last '-' in the directory name with '.' to match versions stored in the database