[Release] update version (#4384)

elastic-vault-github-plugin-prod[bot] · elasticmachine · web-flow · commit ac6af1875293 · 2025-01-30T14:37:51.000+01:00
Co-authored-by: elasticmachine &lt;infra-root+elasticmachine@elastic.co&gt;
diff --git a/version/version.go b/version/version.go
@@ -6,4 +6,4 @@ package version
 
 // DefaultVersion is the current release version of Fleet-server, this version must match the
 // Elastic Agent version.
-const DefaultVersion = "9.0.0"
+const DefaultVersion = "9.1.0"
