Add new 3.x branches to documentation config

Adds the `scylla-3.11.4.x` and `scylla-3.11.5.x` branches to the config,
making them available versions on generated multiversion documentation page.

Author: Bouncheck

docs/source/conf.py

@@ -16,6 +16,8 @@
     'scylla-3.10.2.x',
     'scylla-3.11.0.x',
     'scylla-3.11.2.x',
+    'scylla-3.11.4.x',
+    'scylla-3.11.5.x',
     'scylla-4.7.2.x',
     'scylla-4.10.0.x',
     'scylla-4.11.1.x',
@@ -95,6 +97,8 @@
     'scylla-3.10.2.x',
     'scylla-3.11.0.x',
     'scylla-3.11.2.x',
+    'scylla-3.11.4.x',
+    'scylla-3.11.5.x',
     'scylla-4.7.2.x',
     'scylla-4.10.0.x',
     'scylla-4.11.1.x',