refactor fetch revs warning

dvc/repo/fetch.py

@@ -79,13 +79,13 @@ def outs_filter(out: "Output") -> bool:
             idx.data["repo"].onerror = _make_index_onerror(onerror, rev)
 
             indexes[rev or "workspace"] = idx
-        except Exception as exc:
-            if rev == "workspace" and rev not in revs:
+        except Exception as exc:  # noqa: BLE001
+            if revs and rev == "workspace" and rev not in revs:
                 continue
             if onerror:
                 onerror(rev, None, exc)
             collection_exc = exc
-            logger.exception("failed to collect '%s'", rev or "workspace")
+            logger.warning("failed to collect '%s'", rev or "workspace")
 
     if not indexes and collection_exc:
         raise collection_exc

tests/func/experiments/test_remote.py

@@ -372,6 +372,6 @@ def test_push_invalid_workspace(
     with open("dvc.yaml", mode="a") as f:
         f.write("\ninvalid")
 
-    with caplog.at_level(logging.ERROR, logger="dvc"):
+    with caplog.at_level(logging.WARNING, logger="dvc"):
         dvc.experiments.push(git_upstream.remote, push_cache=True)
         assert "failed to collect" not in caplog.text