Bump older FreeBSD to 13.5, drop some Alpine in CI

Just keep the oldest and newest supported Alpine versions as checking
them all doesn't gain very much alongside all the other builds.

.cirrus.yml

@@ -8,7 +8,7 @@ freebsd_task:
     cpu: 1
     matrix:
       image_family: freebsd-14-1
-      image_family: freebsd-13-3
+      image_family: freebsd-13-4
 
   env:
     # Set to 10 instead of 1 to avoid problems when new commits are submitted
@@ -46,7 +46,7 @@ freebsd_task:
 linux_arm_task:
   name: ARM Linux
   arm_container:
-    image: ubuntu:22.04
+    image: ubuntu:24.04
     memory: 400M
     cpu: 1
 
@@ -91,8 +91,6 @@ linux_musl_task:
     cpu: 1
     matrix:
       image: alpine:3.20
-      image: alpine:3.19
-      image: alpine:3.18
       image: alpine:3.17
 
   env: