build.sh target list: sort as version numbers

before:

Targets:
  centos-10
  centos-7
  rocky-8
  rocky-9
  sdist

after:

Targets:
  centos-7
  centos-10
  rocky-8
  rocky-9
  sdist

build.sh

@@ -110,7 +110,7 @@ usage() {
     echo "  -r URL          - Use URL as registry mirror"
     echo
     echo "Targets:"
-    ls -1 $BUILDER_SUPPORT_ROOT/dockerfiles/Dockerfile.target.* | sed 's/.*Dockerfile.target.//' | sed 's/^/  /'
+    ls -1 $BUILDER_SUPPORT_ROOT/dockerfiles/Dockerfile.target.* | sed 's/.*Dockerfile.target.//' | sed 's/^/  /' | sort -V
 
     echo
     [ -f "$BUILDER_SUPPORT_ROOT/usage.include.txt" ] && cat "$BUILDER_SUPPORT_ROOT/usage.include.txt"

demo/builder-support/dockerfiles/Dockerfile.target.centos-10

@@ -0,0 +1 @@
+# bogus target for sort testing