fix(scripts): isolate diffcheck temporary files

Signed-off-by: fengxueweilai <fengxueweilai@outlook.com>

scripts/diffcheck.sh

@@ -1,8 +1,11 @@
 #!/bin/bash
 
-scripts/buildtable.pl >/tmp/table.mediawiki 2> /dev/null
-diff README.mediawiki /tmp/table.mediawiki | grep '^[<>] |' >/tmp/after.diff || true
-newdiff=$(diff -s scripts/diffcheck.expected /tmp/after.diff -u | grep '^[-+]')
+tmpdir=$(mktemp -d) || exit 1
+trap 'rm -rf "$tmpdir"' EXIT
+
+scripts/buildtable.pl >"$tmpdir/table.mediawiki" 2> /dev/null || exit 1
+diff README.mediawiki "$tmpdir/table.mediawiki" | grep '^[<>] |' >"$tmpdir/after.diff" || true
+newdiff=$(diff -s scripts/diffcheck.expected "$tmpdir/after.diff" -u | grep '^[-+]')
 if [ -n "$newdiff" ]; then
     echo "$newdiff"
     exit 1