etesync-dav: pin dependency versions

pkgs/applications/misc/etesync-dav/default.nix

@@ -13,6 +13,26 @@ let
           inherit version;
           sha256 = "ff177185f891302dc253437fe63081e7a46a4e99aca61dfe086fb23e54fff2dc";
         };
+        disabledTests = [
+          "test_outside_request"
+        ];
+      });
+      werkzeug = super.werkzeug.overridePythonAttrs (old: rec {
+        version = "2.0.3";
+        src = old.src.override {
+          inherit version;
+          sha256 = "b863f8ff057c522164b6067c9e28b041161b4be5ba4d0daceeaa50a163822d3c";
+        };
+      });
+      wtforms = super.wtforms.overridePythonAttrs (old: rec {
+        version = "2.3.3";
+        src = old.src.override {
+          inherit version;
+          sha256 = "81195de0ac94fbc8368abbaf9197b88c4f3ffd6c2719b5bf5fc9da744f3d829c";
+        };
+        checkPhase = ''
+          ${self.python.interpreter} tests/runtests.py
+        '';
       });
     };
   };