Hold memcached at jammy in noble-caracal bundle

The memcached charm has no noble build in the stable channel, so the noble-caracal bundle fails to resolve it on noble. Hold memcached at jammy, matching the other test bundles.

Change-Id: Ia28e08b1d3d87e3d4bbf1e99884a588043b766bc
Signed-off-by: Seyeong Kim <seyeong.kim@canonical.com>

tests/bundles/noble-caracal.yaml

@@ -14,8 +14,8 @@ machines:
     constraints: mem=3072M
   '3':
   '4':
-    # Note that holding memcached at focal as it's not available at jammy yet.
-    series: noble
+    # Note that holding memcached at jammy as it's not available at noble yet.
+    series: jammy
   '5':
   '6':
   '7':
@@ -69,7 +69,7 @@ applications:
   memcached:
     charm: ch:memcached
     num_units: 1
-    series: noble
+    series: jammy
     to:
       - '4'