Move the numeric locale tests to a different file

This lets us check for locales once, and to have littlecheck mark the
test as skipped.

tests/checks/test.fish

@@ -51,20 +51,3 @@ t 5,2
 # CHECKERR: ^
 # CHECKERR: in function 't' with arguments '5,2'
 # CHECKERR: called on line {{\d+}} of file {{.*}}test.fish
-
-if command -q locale
-    # Try to get a comma-using locale.
-    # We have a cheesy list hardcoded, and try to get it in the spelling
-    # that "locale" uses.
-    set -l locales (locale -a)
-    set -l use
-    for locale in de_de fr_fr nl_NL pt_BR
-        set use (string match -ri "$locale.utf.?8" -- $locales)
-        and break
-    end
-    if set -q use[1]
-        set -gx LC_ALL $use
-        # This should succeed without output
-        test 42.5 -gt 37.2
-    end
-end