Fix Citus loadable_libraries (#843)

contrib/citus/Trunk.toml

@@ -7,7 +7,7 @@ description = "Distributed PostgreSQL as an extension."
 homepage = "https://www.citusdata.com/"
 documentation = "https://docs.citusdata.com/en/stable/"
 categories = ["tooling_admin"]
-preload_libraries = ["citus"]
+loadable_libraries = [{ library_name = "citus", requires_restart = true }]
 
 [dependencies]
 apt = ["libpq5", "openssl", "libc6", "liblz4-1", "libzstd1", "libssl3", "libcurl4"]