chore: [NOSNOW] update release notes for 3.13.1 (#2697)

Author: sfc-gh-jwilkowski

RELEASE-NOTES.md

@@ -20,6 +20,16 @@
 
 ## New additions
 
+## Fixes and improvements
+
+
+# v3.13.1
+## Backward incompatibility
+
+## Deprecations
+
+## New additions
+
 ## Fixes and improvements
 * Fixed parsing of --vars provided to `snow dbt execute` subcommands. This allows to pass variables in the same way as to dbt cli, i.e. --vars '{"key": "value"}'