benchmarks: Run glob only once

We assume that you use something like hyperfine to run warmups, like
our driver script does.

This allows the script to be run e.g. in valgrind without being too
much of a pain in the gluteus.

benchmarks/benchmarks/glob.fish

@@ -3,6 +3,5 @@
 # so it's best to build two fishes, check out one version of the repo,
 # and then run this script with both.
 set -l dir (dirname (status current-filename))
-for i in (seq 1 10)
-    echo $dir/../../**
-end
+# No repetitions, this is plenty slow enough.
+echo $dir/../../**