CI: pull requests build on pull_request_target (a conflicting one never fires pull_request); README: contributors and a ledger of their pull requests kept by a workflow

.github/scripts/contributions.sh

@@ -0,0 +1,40 @@
+#!/usr/bin/env bash
+# Regenerates the contributions table in README.md, between its markers, from the repository's
+# pull requests: one row per pull request by anyone but the owner, and a line of totals per
+# contributor. Run by the Contributions ledger workflow when a pull request is opened, merged or
+# closed, and by hand with: gh auth status && .github/scripts/contributions.sh OWNER/REPO
+set -euo pipefail
+REPO=${1:-The412Banner/SteamDeck}
+OWNER=${REPO%%/*}
+ROWS=$(gh api "repos/$REPO/pulls?state=all&per_page=100" --paginate \
+  --jq '.[] | select(.user.login != "'"$OWNER"'")
+        | [.user.login, .number, (.title | gsub("\\|"; "\\\\|")), (.created_at[0:10]),
+           (if .merged_at then "merged " + .merged_at[0:10] elif .state == "closed" then "closed" elif .draft then "draft" else "open" end),
+           .html_url] | @tsv' | sort -t"$(printf '\t')" -k1,1 -k2,2n)
+{
+  echo "<!-- contributions:start -->"
+  echo "_From the repository's pull requests; rewritten when one is opened, merged or closed._"
+  echo
+  echo "| Contributor | Pull request | Opened | State |"
+  echo "|---|---|---|---|"
+  if [ -z "$ROWS" ]; then
+    echo "| — | none yet | | |"
+  else
+    while IFS=$'\t' read -r login num title opened state url; do
+      echo "| [@$login](https://github.com/$login) | [#$num]($url) $title | $opened | $state |"
+    done <<< "$ROWS"
+    echo
+    printf '%s\n' "$ROWS" | awk -F'\t' 'NF { t[$1]++; if ($5 ~ /^merged/) m[$1]++ } END { for (l in t) printf("- **@%s**: %d submitted, %d merged\n", l, t[l], m[l] + 0) }' | sort
+  fi
+  echo "<!-- contributions:end -->"
+} > /tmp/contributions.md
+python3 - <<'PY'
+import re
+s = open('README.md').read()
+new = open('/tmp/contributions.md').read().rstrip('\n')
+out, n = re.subn(r'<!-- contributions:start -->.*?<!-- contributions:end -->', lambda m: new, s, flags=re.S)
+if n != 1:
+    raise SystemExit("README.md has no contributions markers")
+open('README.md', 'w').write(out)
+PY
+echo "README.md: contributions table rewritten"