CI: Don't use matrix when there is no more than 1 task

Signed-off-by: Mobin "Hojjat" Aydinfar <mobin@mobintestserver.ir>

.cirrus.yml

@@ -21,8 +21,7 @@ Dinit with hardening CI_task:
     TEST_LDFLAGS: # ASLR breaks -fsanitize=address,undefined
 
   freebsd_instance:
-    matrix:
-      - image_family: freebsd-14-0
+    image_family: freebsd-14-0
 
   Getting depends_script: pkg update && ASSUME_ALWAYS_YES=YES pkg install gmake m4 file llvm15
   Configure_script: ./configure