Modernize CI scripts

- Use the same configuration as in other repositories

.ci-scripts/indent

@@ -0,0 +1,8 @@
+#!/usr/bin/env bash
+set -e # halt script on error
+
+rm -f /tmp/indent.py
+wget -q https://raw.githubusercontent.com/stfc/Pan-Indenter/master/pan_indent_checker.py -O /tmp/indent.py
+chmod u+x /tmp/indent.py
+
+git diff --name-only --diff-filter=d HEAD^ | grep '\.pan$' | xargs -rn1 /tmp/indent.py check || exit 1

.ci-scripts/panlint

@@ -5,4 +5,4 @@ rm -f /tmp/panlint.py
 wget -q https://raw.githubusercontent.com/quattor/pan/master/panc/src/main/scripts/panlint/panlint.py -O /tmp/panlint.py
 chmod u+x /tmp/panlint.py
 
-git diff --name-only HEAD^ | grep '\.pan$' | xargs -r /tmp/panlint.py || exit 1
+git diff --name-only --diff-filter=d HEAD^ | grep '\.pan$' | xargs -r /tmp/panlint.py || exit 1