docs(security): update supported versions for 1.x

The GitHub Security page wording was outdated, stating Chainloop was in
a pre-1.0 state. Update SECURITY.md to reflect that Chainloop is in 1.x
and security patches are applied to the latest 1.x versions.

Assisted-by: Claude Code
Signed-off-by: Sylwester Piskozub <sylwesterpiskozub@gmail.com>

Chainloop-Trace-Sessions: e4450f40-6eb4-4568-86cf-e52c13ddc72e

Author: Piskoo

SECURITY.md

@@ -2,7 +2,7 @@
 
 ## Supported Versions
 
-Chainloop releases is in a pre-1.0 state, we commit to add security patches to latest versions.
+Chainloop is in a 1.x state. Security patches are applied to the latest 1.x versions.
 
 ## Reporting a Vulnerability