ci: enable nightly on release/2.9 branches

Removes release/2.8 from the nightly runs.

Signed-off-by: Tiago Castro <[email protected]>

Author: tiagolobocastro

.github/workflows/nightly-dispatch.yml

@@ -15,7 +15,7 @@ jobs:
       matrix:
         branch:
           - develop
-          - release/2.8
+          - release/2.9
         repo: [mayastor, mayastor-control-plane, mayastor-extensions]
       fail-fast: false
     steps: