feat(bpapi): Add a header to bpapi.versions file

apps/emqx/priv/bpapi.versions

@@ -1,3 +1,4 @@
+%% This file is automatically generated by `make static_checks`, do not edit.
 {emqx,1}.
 {emqx_authn,1}.
 {emqx_authz,1}.

apps/emqx/test/emqx_bpapi_static_checks.erl

@@ -300,6 +300,9 @@ dump_versions(APIs) ->
     logger:notice("Dumping API versions to ~p", [Filename]),
     ok = filelib:ensure_dir(Filename),
     {ok, FD} = file:open(Filename, [write]),
+    io:format(
+        FD, "%% This file is automatically generated by `make static_checks`, do not edit.~n", []
+    ),
     lists:foreach(
         fun(API) ->
             ok = io:format(FD, "~p.~n", [API])