fix(misc/list-gnophers): make script work when called from any direct…

…ory (gnolang#1308)

\+ use a tmpdir for the csv file.

@moul 

<details><summary>Contributors' checklist...</summary>

- [x] Added new tests, or not needed, or not feasible
- [x] Provided an example (e.g. screenshot) to aid review or the PR is
self-explanatory
- [x] Updated the official documentation or not needed
- [x] No breaking changes were made, or a `BREAKING CHANGE: xxx` message
was included in the description
- [x ] Added references to related issues and PRs
- [x] Provided any useful hints for running manual tests
- [x] Added new benchmarks to [generated
graphs](https://gnoland.github.io/benchmarks), if any. More info
[here](https://github.com/gnolang/gno/blob/master/.benchmarks/README.md).
</details>

misc/list-gnophers/main.sh

@@ -1,12 +1,13 @@
 #!/bin/sh
 
 main() {
+    cd "$(dirname "$0")"
     cd ../..
+    fname="$(mktemp --tmpdir gno_file_commits.XXXXXXXXXX.csv)"
     for file in $(list_gno_files); do
         extract_file_metadata $file
-    done > gno_file_commits.csv
-    echo
-    cat gno_file_commits.csv | sort_by_date | unique_by_author
+    done > "$fname"
+    cat "$fname" | sort_by_date | unique_by_author
 }
 
 list_gno_files() {