test: restore prior state of GLOBIGNORE

I added replaceElectorate.js, so it wouldn't be run a second time by
  yarn ava ./*.test.js
but that caused it to not in CI be found for
  yarn ava ./replaceElectorate.test.js
which seems bizarre to me

a3p-integration/proposals/n:upgrade-next/test.sh

@@ -4,7 +4,7 @@
 # The effects of this step are not persisted in further proposal layers.
 
 # suppress file names from glob that run earlier
-GLOBIGNORE=initial.test.js replaceElectorate.test.js
+GLOBIGNORE=initial.test.js
 
 yarn ava ./replaceElectorate.test.js