chore(release-policy): add 1.13 to the release policy table

Add the new version to the table!

Signed-off-by: Riccardo Mancini <[email protected]>

Author: Manciukic

docs/RELEASE_POLICY.md

@@ -90,6 +90,7 @@ v3.1 will be patched since were the last two Firecracker releases and less than
 
 | Release | Release Date | Latest Patch | Min. end of support | Official end of Support         |
 | ------: | -----------: | -----------: | ------------------: | :------------------------------ |
+|   v1.13 |   2025-08-28 |      v1.13.0 |          2026-02-08 | Supported                       |
 |   v1.12 |   2025-05-07 |      v1.12.1 |          2025-11-07 | Supported                       |
 |   v1.11 |   2025-03-18 |      v1.11.0 |          2025-09-18 | Supported                       |
 |   v1.10 |   2024-11-07 |      v1.10.1 |          2025-05-07 | 2025-05-07 (v1.12 released)     |