fix making too many ssh connections when pushing run cache (#4732) (#4733)

* fix making too many ssh connections when pushing run cache (#4732)

* reformat

* generator should exit on GeneratorExit exception

* Update dvc/tree/ssh/__init__.py

* pool: close on Exception and not BaseException

Co-authored-by: Tomasz Łakota <[email protected]>
Co-authored-by: Ruslan Kuprieiev <[email protected]>
Co-authored-by: Ruslan Kuprieiev <[email protected]>

dvc/tree/pool.py

@@ -11,7 +11,7 @@ def get_connection(conn_func, *args, **kwargs):
     conn = pool.get_connection()
     try:
         yield conn
-    except BaseException:
+    except Exception:
         conn.close()
         raise
     else: