Update CI to FreeBSD 14.2 and 15.0. (#1322)

Author: sunfishcode

.cirrus.yml

@@ -4,7 +4,7 @@
 task:
   name: stable x86_64-unknown-freebsd-14
   freebsd_instance:
-    image_family: freebsd-14-0
+    image_family: freebsd-14-2
   setup_script:
     - curl https://sh.rustup.rs -sSf --output rustup.sh
     - sh rustup.sh --default-toolchain stable -y --profile=minimal
@@ -15,9 +15,9 @@ task:
     - cargo test --workspace --features=all-apis
 
 task:
-  name: stable x86_64-unknown-freebsd-13
+  name: stable x86_64-unknown-freebsd-15
   freebsd_instance:
-    image_family: freebsd-13-3
+    image_family: freebsd-15-0-snap
   setup_script:
     - curl https://sh.rustup.rs -sSf --output rustup.sh
     - sh rustup.sh --default-toolchain stable -y --profile=minimal