remove xt test numbers

diff --git a/xt/author/21-leaks-debug.t b/xt/author/leaks-debug.t
similarity index 100%
rename from xt/author/21-leaks-debug.t
rename to xt/author/leaks-debug.t

diff --git a/xt/author/20-leaks.t b/xt/author/leaks.t
similarity index 100%
rename from xt/author/20-leaks.t
rename to xt/author/leaks.t