fix: lib: use temporary unique file name

The function may be called from scripts that run under different users
and re-using the same file name will run into problems:

/home/debian/.cache/act/2cc577985400de79/hostexecutor/lib/lib.sh: line 96: /tmp/page: Permission denied
curl: (23) Failure writing output to destination

lib/lib.sh

@@ -92,10 +92,11 @@ function retry() {
 function get_versions() {
     local releases=$1
     local page=1
+    local tmp=$(mktemp)
     while true; do
-        curl --fail -sS "$releases?limit=100&page=$page" | jq -r '.[] | .tag_name' >/tmp/page
-        cat /tmp/page
-        if ! test -s /tmp/page; then
+        curl --fail -sS "$releases?limit=100&page=$page" | jq -r '.[] | .tag_name' >$tmp
+        cat $tmp
+        if ! test -s $tmp; then
             break
         fi
         page=$(expr $page + 1)