shell: Add mktemp as a dependency.

shell/caucase.sh

@@ -320,7 +320,7 @@ checkDeps () {
   # Expected builtins & keywords:
   #   alias local if then else elif fi for in do done case esac return [ test
   #   shift set
-  for dep in jq openssl printf echo curl sed base64 cat date; do
+  for dep in jq openssl printf echo curl sed base64 cat date mktemp; do
     command -v $dep > /dev/null || missingdeps="$missingdeps $dep"
   done
   if [ -n "$missingdeps" ]; then