implement code review feedback

Signed-off-by: tarilabs <matteo.mortari@gmail.com>

Co-authored-by: Vanessasaurus <814322+vsoch@users.noreply.github.com>

Author: tarilabs

oras/decorator.py

@@ -52,10 +52,8 @@ def inner(*args, **kwargs):
                     return res
                 except oras.auth.AuthenticationException as e:
                     raise e
-                except requests.exceptions.SSLError:
+                except (requests.exceptions.SSLError, ImportError):
                     raise
-                except ImportError as e:
-                    raise e
                 except Exception as e:
                     sleep = timeout + 3**attempt
                     logger.info(f"Retrying in {sleep} seconds - error: {e}")