Bump version for release.

NEWS

@@ -1,4 +1,4 @@
-2.0.13.dev0
+2.0.13
  * #1054: Allow the Btrfs hook to create and delete snapshots even when running
    as a non-root user. See the documentation for more information:
    https://torsion.org/borgmatic/reference/configuration/data-sources/btrfs/#non-root-user

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "borgmatic"
-version = "2.0.13.dev0"
+version = "2.0.13"
 authors = [
   { name="Dan Helfman", email="witten@torsion.org" },
 ]