Bump version for release.

NEWS

@@ -1,4 +1,4 @@
-1.9.3.dev0
+1.9.3
  * #261 (beta): Add a ZFS hook for snapshotting and backing up ZFS datasets. See the documentation
    for more information: https://torsion.org/borgmatic/docs/how-to/snapshot-your-filesystems/
  * Remove any temporary copies of the manifest file created in support of the "bootstrap" action.

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "borgmatic"
-version = "1.9.3.dev0"
+version = "1.9.3"
 authors = [
   { name="Dan Helfman", email="witten@torsion.org" },
 ]