chore: Unpin upstream version after rebasing

Signed-off-by: Roman Nikitenko <rnikiten@redhat.com>

Author: RomanNikitenko

rebase.sh

@@ -477,7 +477,7 @@ do_rebase() {
 
   echo "Using git $(which git) $(git --version)"
   # grab current upstream version
-  UPSTREAM_VERSION=f4c602693743d533b0a5b96b8d0bc1bd6d041d32
+  UPSTREAM_VERSION=$(git rev-parse upstream-code/main)
   #UPSTREAM_VERSION=1.62.2
 
   # Grab current version