lifecycle: add git_delete_ref

The deploy subtree parks its rollback state in a git ref and has to drop
it again on both the success and the compensated path.

hive-c0re/src/lifecycle/mod.rs

@@ -7,8 +7,8 @@ mod setup;
 mod tests;
 
 pub use git::{
-    git, git_command, git_read_tree_reset, git_rev_parse, git_tag, git_tag_annotated,
-    git_update_ref,
+    git, git_command, git_delete_ref, git_read_tree_reset, git_rev_parse, git_tag,
+    git_tag_annotated, git_update_ref,
 };
 pub use host_config::write_dropins;
 pub use setup::{