fix(SR): add missing mypy annotations

Fix errors reported by mypy update (mypy-2.1.0) on our workflow.

In `SR.py` on `backends`:
```
drivers/SR.py:51: error: Need type annotation for "backends" (hint: "backends: list[<type>] = ...")  [var-annotated]
```

In `test_lock_queue.py`:
```
tests/test_lock_queue.py:15: error: Need type annotation for "saved_queue" (hint: "saved_queue: list[<type>] = ...")  [var-annotated]
```

Signed-off-by: Ronan Abhamon <ronan.abhamon@vates.tech>

Author: Wescoeur

drivers/SR.py

@@ -18,6 +18,8 @@
 # SR: Base class for storage repositories
 #
 
+from sm_typing import List
+
 import VDI
 import xml.dom.minidom
 import xs_errors
@@ -48,7 +50,7 @@ def wrapper(self, *args):
     return wrapper
 
 
-backends = []
+backends: List["SR"] = []
 
 
 def registerSR(SRClass):

tests/test_lock_queue.py

@@ -1,4 +1,4 @@
-from sm_typing import override
+from sm_typing import Any, List, override
 
 import builtins
 import copy
@@ -12,7 +12,7 @@
 
 ## Instead of saving the process queue to disk the mocks will save it here.
 ## It needs to be global because it is shared between threads.
-saved_queue = []
+saved_queue: List[Any] = []
 
 def mock_pickle_dump_fn(*args):
    global saved_queue