Exclude December r1 releases from channel server

Stop offering installs of these releases due to the critical containerd regression.

Signed-off-by: Brad Davidson <brad.davidson@rancher.com>

channel.yaml

@@ -1,10 +1,10 @@
 # Example channels config
 channels:
 - name: stable
-  latest: v1.25.5+k3s1
+  latest: v1.25.4+k3s1
 - name: latest
   latestRegexp: .*
-  excludeRegexp: ^[^+]+-
+  excludeRegexp: (^[^+]+-|v1\.25\.5\+k3s1|v1\.26\.0\+k3s1)
 - name: testing
   latestRegexp: -(alpha|beta|rc)
 - name: v1.16
@@ -40,10 +40,13 @@ channels:
   excludeRegexp: ^[^+]+-
 - name: v1.24
   latestRegexp: v1\.24\..*
-  excludeRegexp: ^[^+]+-
+  excludeRegexp: (^[^+]+-|v1\.24\.9\+k3s1)
 - name: v1.25
   latestRegexp: v1\.25\..*
-  excludeRegexp: ^[^+]+-
+  excludeRegexp: (^[^+]+-|v1\.25\.5\+k3s1)
+- name: v1.26
+  latestRegexp: v1\.26\..*
+  excludeRegexp: (^[^+]+-|v1\.26\.0\+k3s1)
 github:
   owner: k3s-io
   repo: k3s