Fix individual lockfile updates

The original update uses a syntax not supported by `nix --version`:
`1.18`

pkgs/action-flake-update-pr-clan-individual/script.sh

@@ -23,16 +23,25 @@ inputs=$(nix flake metadata --json | jq '.locks.nodes | keys[]' --raw-output | g
 
 for input in $inputs;
 do
+	target_branch="update-${input}"
+
 	echo "updating input: ${input}"
-	echo "checking out main"
+	echo "checking out: git checkout main"
 	git checkout main
+	git checkout -b "$target_branch"
+	echo "checking out: git checkout -b update-${input}"
 	export PR_TITLE="Automatic flake update - ${input} - ${today_minutes}"
 	export REMOTE_BRANCH="flake-update-${input}-${today}"
 	echo "action-ensure-tea-login"
 	action-ensure-tea-login
 	echo "action-flake-update: ${input}"
 	action-flake-update "$input"
-	echo "action-create-pr"
-	action-create-pr --assignees clan-bot
+	echo "check diff"
+	if git diff --quiet main.."$target_branch" --;then
+		echo "No lockfile changes for input: ${input}"
+	else
+		echo "action-create-pr"
+		action-create-pr --assignees clan-bot
+	fi
 done
 

pkgs/action-flake-update/script.sh

@@ -1,7 +1,16 @@
 #!/usr/bin/env bash
 set -euo pipefail
 
-COMMIT_MSG="update flake lock - $(date --iso-8601=minutes)"
+NIX_VERSION=$(nix --version)
+echo "Nix version: $NIX_VERSION"
 
+if [ -z "${*}" ];then
+COMMIT_MSG="update flake lock - $(date --iso-8601=minutes)"
 nix --experimental-features "nix-command flakes" \
-  flake update --commit-lock-file --commit-lockfile-summary "$COMMIT_MSG" "$@"
+  flake update --commit-lock-file --commit-lockfile-summary "$COMMIT_MSG"
+else
+# Support for ancient nix versions
+COMMIT_MSG="update flake lock - ${*} - $(date --iso-8601=minutes)"
+nix --experimental-features "nix-command flakes" \
+  flake lock --commit-lock-file --commit-lockfile-summary "$COMMIT_MSG" --update-input "${@}"
+fi