tools: Fix sign and docker target detection when passed as single argument

The sign target detection uses pattern matching that requires spaces on
both sides of "sign" in the TARGETS variable. When only "sign" is passed
as an argument, TARGETS becomes " sign" (leading space only), causing
the condition to fail.

Add an additional pattern match to detect "sign" with a leading space
but no trailing space, which occurs when "sign" is the only target or
the last target in the list.

This regression seems to have been exposed by GitHub Actions runner
updates (Ubuntu 22.04 → 24.04), which changed argument passing behavior.

Changelog-None: Fixes the release signing issue in CI only.

Author: ShahanaFarooqui

tools/build-release.sh

@@ -209,7 +209,7 @@ for target in $TARGETS; do
     esac
 done
 
-if [ -z "${TARGETS##* docker *}" ]; then
+if [ -z "${TARGETS##* docker *}" ] || [ -z "${TARGETS##* docker}" ]; then
     echo "Building Docker Images"
     DOCKER_USER="elementsproject"
     echo "Creating multi-platform images tagged as $VERSION and latest"
@@ -230,7 +230,7 @@ if [ -z "${TARGETS##* docker *}" ]; then
     echo "Pushed multi-platform images tagged as $VERSION and latest"
 fi
 
-if [ -z "${TARGETS##* sign *}" ]; then
+if [ -z "${TARGETS##* sign *}" ] || [ -z "${TARGETS##* sign}" ]; then
     echo "Signing Release"
     cd release/ || exit
     sha256sum clightning-"$VERSION"-*.tar.* clightning-"$VERSION".zip > SHA256SUMS-"$VERSION"