CI: allow whitespace in *.test_input test files (#8101)

Some of our test input files require trailing white space. We already
allow this for `*.gold` files. Naming all such input files `*.gold`
which are not in fact gold files would be confusing. This tweaks our CI
formatting check to also ignore the more generic `.test_input` extension
so that people writing tests with trailing white space can use that
extension to skip the trailing white space check in ci.
1 file changed