Cirrus-CI: use built-in submodule support

cirruslabs/cirrus-ci-docs@f7d2939

.cirrus.yml

@@ -9,21 +9,18 @@ freebsd_instance:
 
 env:
   CIRRUS_CLONE_DEPTH: 1
+  CIRRUS_CLONE_SUBMODULES: true
 
 task:
   timeout_in: 120m
   install_script:
   - pkg install -y llvm11
-  - pkg install -y git-lite
   setup_script:
   - uname -a
   - df -m
   - pw useradd user
   - mkdir -p /usr/obj/$(pwd -P)
   - chown user:user /usr/obj/$(pwd -P)
-  submodules_script:
-  - git submodule init
-  - git submodule update
   script:
   - su user -c "make -j$(sysctl -n hw.ncpu) CROSS_TOOLCHAIN=llvm11 WITHOUT_TOOLCHAIN=yes buildworld buildkernel"
   post_script: