Port Relx compatibility fix prior to version bump

Manyally applies erlware/relx#941 to vendored
files, since the relx release for it isn't in place just yet but we need
OTP-27 compatibility.

Author: ferd

vendor/relx/priv/templates/install_upgrade_escript

@@ -2,6 +2,7 @@
 %%! -noinput
 %% -*- mode: erlang;erlang-indent-level: 4;indent-tabs-mode: nil -*-
 %% ex: ft=erlang ts=4 sw=4 et
+-mode(interpret).
 
 -define(TIMEOUT, 300000).
 -define(INFO(Fmt,Args), io:format(Fmt,Args)).

vendor/relx/priv/templates/nodetool

@@ -10,6 +10,7 @@
 %% relx when OTP-23 becomes the earliest support version of OTP.
 %%
 %% -------------------------------------------------------------------
+-mode(interpret).
 
 main(Args) ->
     %% Extract the args