docs: Update RN for 3.5.7 (#19497)

Author: JStickler

docs/sources/release-notes/v3-5.md

@@ -66,6 +66,13 @@ For important upgrade guidance, refer to the [Upgrade Guide](https://grafana.com
 
 ## Bug fixes
 
+### 3.5.7 (2025-10-13)
+
+This release fixes a build issue in 3.5.6 where it was not built with Go 1.24.8 as expected, but Go 1.24.1.
+
+* **build:** Update rpm signature config ([#19476](https://github.com/grafana/loki/issues/19476)) ([#19483](https://github.com/grafana/loki/issues/19483)) ([d5b382b](https://github.com/grafana/loki/commit/d5b382b90738505d8bf7217ff3a1a8c90fc09b7e)).
+* **build:** Update loki build image ([#19473](https://github.com/grafana/loki/issues/19473)) ([#19474](https://github.com/grafana/loki/issues/19474)) ([c70476a](https://github.com/grafana/loki/commit/c70476ab0fec3bef906f86ac72c2256bb94f9624)).
+
 ### 3.5.6 (2025-10-10)
 
 * **deps:** Remove CVE GHSA-2464-8j7c-4cjm ([#19469](https://github.com/grafana/loki/issues/19469)) ([f2a304a](https://github.com/grafana/loki/commit/f2a304a34d0eb35be6c09e3f525ec6986a003275)).