OpenFOAM-org: Add missing dependency on readline for @:9 (#44482)

The setSet tool (removed in version 10) has an optional dependency on readline.
The build script will use the system readline if not provided by Spack.

var/spack/repos/builtin/packages/openfoam-org/package.py

@@ -106,6 +106,8 @@ class OpenfoamOrg(Package):
     depends_on("zlib-api")
     depends_on("flex")
     depends_on("cmake", type="build")
+    # The setSet tool (removed in version 10) depends on readline
+    depends_on("readline", when="@:9")
 
     # Require scotch with ptscotch - corresponds to standard OpenFOAM setup
     depends_on("scotch~metis+mpi~int64", when="+scotch~int64")